2nd Grade Math Compilation - By
Transcript
| 00:00 | wow . We are going to learn so many cool | |
| 00:03 | things on this home school pop video . All right | |
| 00:06 | . What's the first thing we should learn ? How | |
| 00:09 | about perimeter ? All right . Let's show you how | |
| 00:14 | fun this is . Imagine I'm a race car driver | |
| 00:18 | , Right ? And don't make fun of my car | |
| 00:20 | . Okay . This is this is a perfectly good | |
| 00:22 | car to do a racing , right ? It's very | |
| 00:24 | fast . It's got the bells has got the whistles | |
| 00:27 | . It's a great race car . Okay , stop | |
| 00:30 | laughing at it . Okay , now , imagine this | |
| 00:34 | is the race car course that I'm driving on , | |
| 00:37 | Right ? It's going around an oval . It's going | |
| 00:40 | around a shape . If I was wondering , how | |
| 00:46 | far is it around the track ? What's the distance | |
| 00:49 | around the shape , then ? I would need to | |
| 00:52 | know the perimeter . The perimeter is the distance around | |
| 00:57 | a shape . Wait , wait , wait . What | |
| 01:01 | is the perimeter ? The perimeter of a shape is | |
| 01:07 | the distance around a shape . And it's easy to | |
| 01:13 | find . You can find the perimeter of a shape | |
| 01:16 | by adding all of the sides that will tell you | |
| 01:20 | what the distance around the shape is . Great . | |
| 01:26 | Now let's practice finding the perimeter . Look at this | |
| 01:29 | triangle . What is the perimeter of this triangle ? | |
| 01:34 | Okay . First we need to know how long all | |
| 01:38 | of the sides are . Then we can figure out | |
| 01:41 | the perimeter with this triangle . All three sides are | |
| 01:47 | the same length . So how long are they ? | |
| 01:50 | Let's pretend we measured it and each side is 10 | |
| 01:54 | cm . Now , remember to find the perimeter of | |
| 02:00 | a shape . We need to know the distance around | |
| 02:02 | the whole shape . So we just add the sides | |
| 02:05 | together . What's 10 plus 10 plus 10 ? That's | |
| 02:10 | 3 10s . What does that equal ? Yeah , | |
| 02:15 | 30 . Mhm . Awesome . The perimeter of this | |
| 02:20 | triangle is 30 centimeters . Remember cm is an abbreviation | |
| 02:26 | for centimeters 30 centimeters . Is the perimeter of this | |
| 02:30 | triangle . Okay , let's try this one . What | |
| 02:37 | is the perimeter of this square ? First we need | |
| 02:43 | to know how long all the sides of the square | |
| 02:46 | are . Then we can figure out the perimeter of | |
| 02:48 | the square . Okay , so this is a square | |
| 02:53 | . It has four sides and all four sides are | |
| 02:57 | the same side . Let's pretend we measured it and | |
| 03:01 | each side is one yard . Remember why D is | |
| 03:06 | an abbreviation for the distance of a yard ? Each | |
| 03:10 | side is one yard . Remember the perimeter is the | |
| 03:17 | distance around a shape . So we'll need to add | |
| 03:21 | all of these sides up . Okay , what's one | |
| 03:25 | plus one plus one plus one ? Yeah . Four | |
| 03:33 | . The perimeter of this square is four yards . | |
| 03:38 | The perimeter , remember , is the distance around a | |
| 03:41 | shape . If you were to go around this entire | |
| 03:43 | square it would be four yards . Okay , this | |
| 03:51 | is the final one . What is the perimeter of | |
| 03:54 | this rectangle ? Well , first we need to know | |
| 03:59 | how long all the sides of the rectangle are , | |
| 04:03 | then we can figure out the perimeter . Remember . | |
| 04:09 | A rectangle has four sides and two of the sides | |
| 04:13 | are shorter than the other two sides with this rectangle | |
| 04:18 | . Let's pretend we measured it at one m on | |
| 04:21 | the short sides and three m on the longer sides | |
| 04:28 | . Okay , remember to get the perimeter , we | |
| 04:30 | have to add all of the sides together . So | |
| 04:33 | we're going to be adding four numbers together again . | |
| 04:36 | To make it easier , we're going to group the | |
| 04:38 | smaller numbers together and then put the larger numbers in | |
| 04:43 | our equation . What's one plus one plus three plus | |
| 04:49 | three ? Those are all the sides . What's one | |
| 04:52 | plus one plus three plus three ? Yeah . Yeah | |
| 04:59 | . Eight . Mhm . That means the perimeter of | |
| 05:06 | this rectangle is eight m , wow . We told | |
| 05:12 | you it was gonna be fun . Oh , it's | |
| 05:14 | such a blast . Finding the perimeter the perimeter is | |
| 05:17 | so much fun to find . It's like a game | |
| 05:22 | . Remember you can find the perimeter of a shape | |
| 05:26 | by adding all of the sides and the perimeter of | |
| 05:32 | a shape is the distance around a shape I'm so | |
| 05:40 | proud of you , I'm so proud of . Now | |
| 05:43 | . You know how to find the perimeter of something | |
| 05:45 | . The perimeter is the distance around a shape . | |
| 05:48 | I can find the perimeter of this tablet . Right | |
| 05:51 | ? All I would need to do is measure each | |
| 05:53 | side and add them together . And I would find | |
| 05:57 | the perimeter right now . I I gotta find an | |
| 06:00 | internet connection . There's no Wifi out here . There's | |
| 06:02 | no reason to be in the desert . I need | |
| 06:04 | water . There's not . This doesn't make any sense | |
| 06:07 | . Okay , so I'm gonna go you go ahead | |
| 06:11 | and find perimeter . Enjoy the perimeter is a distance | |
| 06:14 | around the shape . Go have fun . Thanks for | |
| 06:17 | watching . Yeah , Yeah . We are so happy | |
| 06:26 | to have you with us . I mean you are | |
| 06:28 | so awesome . You really are . Oh , you | |
| 06:31 | like my poster Mr Whiskers poster . You know , | |
| 06:35 | it's pretty cool . Pretty cool . You know , | |
| 06:38 | it's a pretty cool poster . Pretty cool cat too | |
| 06:41 | . I wonder what he would like to learn about | |
| 06:43 | next if he would learn from one of our videos | |
| 06:46 | , what would he like to learn next ? How | |
| 06:49 | about let's learn about fractions ? Fractions are so awesome | |
| 06:58 | and so much fun . Yeah , many of you | |
| 07:02 | think so too . A couple of weeks ago we | |
| 07:04 | set up a poll on our channel and many of | |
| 07:07 | you voted for fractions as our next math video . | |
| 07:11 | That's really awesome . Thanks everyone for voting . And | |
| 07:14 | don't worry , we'll make the other two videos to | |
| 07:16 | later on . But this is all about fractions . | |
| 07:20 | All right , well let's start here . What is | |
| 07:25 | a fraction when we say the word fraction , What | |
| 07:27 | do we mean ? What is a fraction ? Well | |
| 07:33 | , a fraction is something that shows parts of a | |
| 07:35 | whole , let's say there's this lady named Cindy . | |
| 07:42 | Cindy has a pizza , which is great . She | |
| 07:47 | loves pizza . So yeah , me pizza . But | |
| 07:53 | then her friend chomsky arrives . You remember chomsky chomsky | |
| 07:57 | likes pizza too and he's a little bit hungry . | |
| 08:00 | So maybe Cindy isn't going to eat the whole pizza | |
| 08:03 | now , maybe they're gonna split it . What do | |
| 08:06 | you think ? So they split the pizza in half | |
| 08:11 | . Each of them get one half of the pizza | |
| 08:14 | that neat . Then everyone has pizza . Each of | |
| 08:18 | them have one half of the pizza . They split | |
| 08:21 | it right down the middle . Now remember a fraction | |
| 08:27 | is something that shows parts of a whole . So | |
| 08:32 | here is what the fraction looks like a one a | |
| 08:36 | line and the two that is the fraction . One | |
| 08:40 | half each of them . Cindy and chomsky get one | |
| 08:44 | half of the pizza . So this is one half | |
| 08:51 | . It's a very important fraction because we use it | |
| 08:55 | all the time . Now . You might be wondering | |
| 08:57 | what do the numbers mean ? And how does it | |
| 09:00 | show one half ? Well , the bottom number shows | |
| 09:06 | the total number of parts . The top number shows | |
| 09:13 | how many parts we are talking about . Pretty simple | |
| 09:17 | . Let's go back to our example . There are | |
| 09:23 | a total of two parts to the pizza , so | |
| 09:26 | there's a two on the bottom and Cindy just gets | |
| 09:30 | one part , that's the part we're talking about . | |
| 09:33 | So Cindy gets just one half of the pizza , | |
| 09:37 | she doesn't get the whole thing , she gets just | |
| 09:40 | one part , she gets one half . The bottom | |
| 09:45 | number of a fraction is called the denominator . The | |
| 09:49 | denominator is the total number of parts . The top | |
| 09:57 | number is called the numerator . The numerator tells us | |
| 10:00 | how many parts we are talking about in this case | |
| 10:04 | Cindy is having one part of the pizza , the | |
| 10:08 | other part of course is going to chomsky , let's | |
| 10:13 | try this , let's say there's another pizza and this | |
| 10:16 | pizza has four parts . The number four is the | |
| 10:21 | denominator because there are four pieces of pizza , four | |
| 10:27 | parts let's say kelly shows up and wants to have | |
| 10:34 | one part of the pizza , one piece of the | |
| 10:38 | pizza , the numerator or the top number of the | |
| 10:43 | fraction is the number one because kelly is having one | |
| 10:49 | part or one piece of the pizza , kelly is | |
| 10:54 | having 1/4 of the pizza . Pretty simple , pretty | |
| 10:58 | fun , fractions are awesome . Mm Now we're going | |
| 11:04 | to need your help help us figure out what fraction | |
| 11:10 | is it ? What fraction is it ? Wow , | |
| 11:15 | we're gonna have a great time . Let's say we | |
| 11:20 | have a group of five sports balls . One is | |
| 11:24 | a basketball , the other four are soccer balls . | |
| 11:30 | Let's figure out what fraction of the balls are basketballs | |
| 11:36 | . What fraction of the balls are basketballs . So | |
| 11:45 | we know a fraction has a line in the middle | |
| 11:47 | and the top number is the numerator and the bottom | |
| 11:50 | number is the denominator . The denominator shows us the | |
| 11:55 | total number of parts or units . How many sports | |
| 11:59 | balls are there ? Yeah . 5 . 5 is | |
| 12:07 | the denominator . Good job . Now remember we're asking | |
| 12:12 | for the fraction of sports balls that are basketball's . | |
| 12:17 | So how many basketballs are there ? Yeah , just | |
| 12:24 | one . The number one is the numerator . So | |
| 12:29 | 1/5 of the sports balls are basketball's 1/5 . Great | |
| 12:36 | job . Let's try this final example . Let's say | |
| 12:41 | there are five pets . 5 pets two of them | |
| 12:46 | are dogs and three of them are cats . What | |
| 12:54 | fraction of the pets are cats ? Huh ? That's | |
| 12:57 | a good question . What fraction of the pets are | |
| 13:01 | cats ? Remember ? Here's what a fraction looks like | |
| 13:06 | . It's got a line in the middle with the | |
| 13:08 | top number being the numerator . And the bottom number | |
| 13:11 | is the denominator . So the total number of pets | |
| 13:19 | is five . What number is the denominator ? What | |
| 13:22 | number goes on ? The bottom ? Yeah . 5 | |
| 13:28 | . 5 is the denominator . It tells us the | |
| 13:31 | total number of bets . Remember we're asking for the | |
| 13:38 | fraction of the pets that are cats ? How many | |
| 13:42 | cats are there ? Yeah . three . So what's | |
| 13:47 | the numerator ? Yeah . 33 is the numerator . | |
| 13:54 | 3/5 of the pets are cats , wow , that | |
| 13:59 | was so cool . But none of those catcher is | |
| 14:06 | special to me . As you . Mr whiskers . | |
| 14:09 | Not even a fraction of my heart belongs to my | |
| 14:12 | whole heart . I love you . Mr whiskers . | |
| 14:15 | I do I do . A fraction is something that | |
| 14:21 | shows parts of a whole . The top number of | |
| 14:28 | a fraction is the numerator . How many parts we | |
| 14:31 | are talking about ? And the bottom number of a | |
| 14:34 | fraction is the denominator . The total number of parts | |
| 14:41 | . Oh wow . Look it's the homophone cow homophone | |
| 14:44 | cow hama phone cattle . You're just walking . You're | |
| 14:49 | just just gonna ignore me . I see how it | |
| 14:52 | is . Okay so you're upset that we haven't included | |
| 14:55 | you in other videos . What do you call this | |
| 14:57 | ? You know you're in a compilation video . That's | |
| 15:00 | cool too . All right I need to talk to | |
| 15:03 | the homophone cow . But in the meantime let's learn | |
| 15:08 | about multiplication . You're gonna learn how to multiply and | |
| 15:12 | if that sounds really scarier , if that sounds like | |
| 15:15 | a difficult thing , it's just because you don't know | |
| 15:18 | how to do it yet . Once you learn the | |
| 15:20 | game , once you learn the process , it's fun | |
| 15:23 | . It's awesome . You see , multiplying is like | |
| 15:28 | being a detective , you're cracking a code , which | |
| 15:31 | is so cool , you're solving mysteries like legit mysteries | |
| 15:35 | . Like I'm I'm in an office building right now | |
| 15:38 | . There's a cake behind me . For some reason | |
| 15:40 | , I'm looking out right now , are you guys | |
| 15:42 | ? And I see that you're like , whoa , | |
| 15:43 | we're gonna multiply thanks . And once you learn it's | |
| 15:47 | just a game , so buckle in for the fun | |
| 15:50 | and the learning , let's say you have two bikes | |
| 15:55 | and for some reason they look the exact same and | |
| 15:59 | somebody wants to give you an air pump . They | |
| 16:04 | ask a simple question . How many tires do you | |
| 16:07 | have to take care of you to figure that out | |
| 16:11 | ? We're gonna use multiplication . We're gonna play the | |
| 16:14 | game . It's gonna be awesome . Okay , So | |
| 16:19 | here is how multiplication works . So we put the | |
| 16:24 | number that's in each group and then we put this | |
| 16:28 | X . Which means times and then the number of | |
| 16:31 | groups . So that tells us how many times that | |
| 16:34 | number is going to show up , and then we | |
| 16:36 | add them all together . And you've got your answer | |
| 16:39 | . Isn't that cool ? Mhm . And just a | |
| 16:43 | side note to work , there has to be the | |
| 16:45 | same number in each group . Big people . Now | |
| 16:51 | remember , we're trying to figure out how many tires | |
| 16:53 | you have to take care of if you have two | |
| 16:56 | bicycles . All right now , we have the wheels | |
| 17:00 | under each bike . Each bike has two wheels 12 | |
| 17:09 | So we write down A . To each bike has | |
| 17:13 | two wheels . Remember the first number we write down | |
| 17:20 | with multiplication is the number in each group . Then | |
| 17:27 | we write an X . This X means times two | |
| 17:32 | times . It's the symbol of multiplication . Right ? | |
| 17:38 | All right . The second number we Right . Are | |
| 17:40 | the number of groups . You can see them here | |
| 17:42 | . How many groups do we have of two ? | |
| 17:46 | How many ? Yeah , too . So it reads | |
| 17:52 | two times to you to figure this out . We | |
| 17:58 | are going to skip . Count by two , 24 | |
| 18:05 | That means two times two equals four . If you | |
| 18:12 | have two bikes , that means you have four wheels | |
| 18:15 | . 22 times is four . Remember , this is | |
| 18:22 | how multiplication works . The number in each group times | |
| 18:28 | the number of groups equals your answer . The of | |
| 18:34 | course to work . There has to be the same | |
| 18:37 | number in each group . All right , let's take | |
| 18:41 | this to the next level . Let's say someone has | |
| 18:43 | four bikes and here are their wheels . You know | |
| 18:52 | how to do this ? Now , each bike has | |
| 18:55 | two wheels . To the first number we write down | |
| 18:57 | is the number two . That's the number in each | |
| 19:00 | group . We're gonna put the time symbol there and | |
| 19:06 | count the number of groups . 1234 So , it's | |
| 19:10 | two times four . This is so much fun . | |
| 19:15 | This is multiplication . Now , let's skip . Count | |
| 19:22 | to get the answer . 2468 Eight is our answer | |
| 19:31 | . There are eight wheels . Two times four equals | |
| 19:34 | eight . This is how multiplication works . Mhm . | |
| 19:42 | We put the number in each group times the number | |
| 19:45 | of groups . And we get our answer . You're | |
| 19:50 | getting the hang of it . All right , let's | |
| 19:52 | try this one . Mhm . Let's say you buy | |
| 19:57 | three packs of trading cards . Let's say each pack | |
| 20:03 | had five cards in it . Huh ? That's pretty | |
| 20:06 | good amount . So , three packs of five cards | |
| 20:11 | sugar . How many cards did you get in total | |
| 20:15 | ? It's a really great question . Sounds like we're | |
| 20:19 | gonna need to multiply . So each group has five | |
| 20:26 | . So that's the first thing . We write down | |
| 20:28 | the number in each group . That's five . Put | |
| 20:32 | the multiplication sign which is the X . Which means | |
| 20:35 | times five times how many groups are there ? 123 | |
| 20:45 | So the second number is 35 times three . What's | |
| 20:51 | five times three ? We're gonna skip count to find | |
| 20:55 | out . 5 , 10 , 15 . Five times | |
| 21:04 | three equals 15 . You have 15 trading cards . | |
| 21:12 | All right , this is how it works . You | |
| 21:16 | take the number in each group times the number of | |
| 21:19 | groups . And you get your answer . Now here | |
| 21:26 | are some multiplication tricks that are going to be really | |
| 21:29 | sneaky ways that you can figure out multiplication problems really | |
| 21:34 | , really quickly . Here's the trick . If you | |
| 21:37 | multiply any number by zero , you always get zero | |
| 21:42 | Always , you always get zero . Here's an example | |
| 21:49 | , five times zero equals zero . When you have | |
| 21:53 | zero groups of five , that means you have zero | |
| 21:56 | , there are none . Whenever you multiply any number | |
| 21:59 | by zero , you always get 0 , 100 times | |
| 22:03 | zero equals zero . My friend . Even if zero | |
| 22:11 | is the first number in the equation , you still | |
| 22:13 | always get zero . When you multiply by any number | |
| 22:17 | . For example , zero times 11 equals zero and | |
| 22:25 | zero times 1000 equal zero . If you multiply any | |
| 22:30 | number by zero , you always get zero . Oh | |
| 22:35 | , this has been so much fun . Here is | |
| 22:37 | the next trick . If you multiply any number by | |
| 22:45 | one , it stays the same . Look at these | |
| 22:49 | seven times one equals 7 , 100 times one equals | |
| 22:53 | 130 . 3 times one equals 33 mm . If | |
| 23:01 | you flip them , the answer stays the same one | |
| 23:04 | times seven equals 71 times 100 equals 101 times 33 | |
| 23:09 | equals 33 . Honestly , the order of the multiplied | |
| 23:13 | numbers does not change the answer . Yeah . If | |
| 23:20 | you were to flip the number of groups and the | |
| 23:22 | number of each group , you would still get the | |
| 23:25 | same answer . So we still recommend this way . | |
| 23:30 | So simple . The number in each group times the | |
| 23:33 | number of groups to get your answer . So the | |
| 23:40 | two tricks have been , If you multiply any number | |
| 23:43 | by zero , you always get zero and if you | |
| 23:50 | multiply any number by one , it stays the same | |
| 23:54 | . The final multiplication trick is to use multiplication tables | |
| 24:04 | . They come in all shapes and sizes , but | |
| 24:07 | they are all helpful , especially as you're first learning | |
| 24:10 | how to multiply . Here are some examples of multiplication | |
| 24:14 | tables . There's a table for all of the numbers | |
| 24:17 | from 1 to 10 mm . Some kids memorize tables | |
| 24:25 | like these so that they'll know right off the bat | |
| 24:28 | in a moment . What an answer could be for | |
| 24:31 | certain multiplication problems . This is how multiplication works . | |
| 24:36 | The number in each group times the number of groups | |
| 24:40 | gives us our answer . Oh , this is such | |
| 24:47 | a heavy cart . Oh my goodness . It's hard | |
| 24:52 | work . You know , a lot of times learning | |
| 24:54 | can be hard work too . But we hope that | |
| 24:57 | these videos are really helpful . Make learning fun . | |
| 25:00 | So that learning is hard like pushing this cart . | |
| 25:03 | Oh my goodness ! All right , what's the next | |
| 25:06 | thing we should learn about ? Let's learn about three | |
| 25:12 | dimensional shapes . This is gonna be awesome . Love | |
| 25:15 | the three d shapes . A lot of people know | |
| 25:17 | the two d shapes . You might not know the | |
| 25:19 | three D shapes . You're in the right place . | |
| 25:22 | Before we get started . We just dance here real | |
| 25:24 | quick . This is really cool music . I really | |
| 25:27 | like this . You know , I like to dance | |
| 25:29 | . You know , some people they're not dancers . | |
| 25:30 | You know , I dance , I dabble and dancing | |
| 25:34 | , you know ? All right , that's enough . | |
| 25:37 | Can somebody turn that music off ? Seriously ? I | |
| 25:40 | can't teach like this . I can't teach with this | |
| 25:42 | music going on . You know , I feel like | |
| 25:44 | I'm in a candy shop . Let's just start the | |
| 25:46 | music off , please . Thanks . So here they | |
| 25:51 | are our old friends , the two D shapes . | |
| 25:54 | You're familiar with these . You know , you're familiar | |
| 25:56 | with the circle , the oval , the triangle , | |
| 26:00 | the pentagon , the trapezoid , the hex a gone | |
| 26:05 | , the square , the rectangle , the parallelogram in | |
| 26:08 | the octagon . These are all our our shapes , | |
| 26:12 | r two D shapes , you know , But these | |
| 26:14 | are old family friends of ours . We don't want | |
| 26:17 | to just Forget about these before we look at 3D | |
| 26:20 | shapes . It's really important for us to look at | |
| 26:23 | these shapes again because these are old friends . So | |
| 26:26 | we're gonna look at each one of these one by | |
| 26:28 | one . Just to make sure you know who they | |
| 26:31 | are . Before we learn all these new shapes . | |
| 26:35 | This first shape doesn't even need an introduction . It's | |
| 26:38 | the circle , the circle , that round figure . | |
| 26:42 | It's awesome . We love this shape . It's one | |
| 26:45 | of the first ones we ever learn the circle . | |
| 26:50 | This next shape is one of the stretchy shapes . | |
| 26:53 | The oval , it's like a circle got stretched out | |
| 26:56 | . Its elongated . It's a tremendous shape . The | |
| 27:01 | oval , mm . Mhm . Here's another familiar shape | |
| 27:07 | . The triangle . Three sides . We love the | |
| 27:12 | triangle . The triangle is great , the three sighted | |
| 27:15 | friend . Three sides . A triangle . Wait , | |
| 27:21 | I keep saying we love the shapes . I mean | |
| 27:23 | we like the shapes . But do you love the | |
| 27:26 | shapes ? Do I love the shapes ? I mean | |
| 27:29 | I don't know . I need to take it easy | |
| 27:32 | here , huh ? All right , let's keep going | |
| 27:35 | . Mhm . Ah The square of four sides all | |
| 27:39 | equal . You know the square is good . The | |
| 27:42 | squares a good shape . You know sometimes you just | |
| 27:45 | need a square . Sometimes you just need a square | |
| 27:51 | . Here's the rectangle . The rectangle is longer than | |
| 27:55 | the square because not all four sides are equal . | |
| 28:00 | The rectangle . I know I'm we're in the middle | |
| 28:06 | of something here , but I have to share this | |
| 28:07 | . Okay , so what do you call a hamster | |
| 28:11 | with the top hat ? Abraham stir Lincoln . I | |
| 28:18 | digress the trapezoid , a cool shape with two of | |
| 28:24 | the sides being parallel to each other . In the | |
| 28:27 | parallelogram . Another four sided shape . Both pairs of | |
| 28:31 | sides are parallel to each other and finally the pentagon | |
| 28:37 | with five sides . The hex a gone with six | |
| 28:40 | sides and the octagon with eight sides . What awesome | |
| 28:45 | shapes . So let's go ahead and do a quick | |
| 28:52 | to D shaped quiz . I need your help . | |
| 28:55 | I want to see if you really learn these , | |
| 28:57 | if you really know these before we get into the | |
| 28:59 | three D . Shape . So help me out here | |
| 29:01 | we're gonna have an awesome time . Wait what ? | |
| 29:06 | What ? It's not my birthday . Oh well what | |
| 29:11 | type of shape is on the top ? Yeah . | |
| 29:17 | Yeah . A circle . What type of shape is | |
| 29:21 | in the middle ? A square awesome . Okay now | |
| 29:29 | what shape is on the bottom ? Of course A | |
| 29:36 | triangle awesome job . Now we've got more , this | |
| 29:42 | is a little trickier . Which shape is in the | |
| 29:44 | middle ? This yeah a trapezoid . Which shape is | |
| 29:53 | on the right , The pentagon . Good job . | |
| 30:00 | And which shape is on the left . Yeah the | |
| 30:08 | square . Now try these . Which shape is on | |
| 30:15 | the bottom ? Yeah . The oval . Which shape | |
| 30:22 | is on the top . Yeah . Yeah . The | |
| 30:29 | parallelogram which shape is in the middle ? Yeah . | |
| 30:36 | All right . The rectangle . Great job . All | |
| 30:42 | right . The last one . Which shape is on | |
| 30:46 | the left ? Yeah . The hexagon . Which shape | |
| 30:55 | is on the right , Great . The octagon . | |
| 31:03 | And which shape is in the middle ? Yeah , | |
| 31:08 | phenomenal . The pentagon . All right . We're ready | |
| 31:14 | to learn the 3D shapes . We're going to learn | |
| 31:16 | how to identify the three dimensional shapes . If you | |
| 31:21 | struggle through the quiz you might want to watch the | |
| 31:23 | first part of the video again . Otherwise let's get | |
| 31:26 | started . So as we're starting out it's important to | |
| 31:31 | remember what makes a 3D shape a 3D shape . | |
| 31:35 | There's an old rhyme that says three D shapes are | |
| 31:39 | fat , not flat . And you can see that | |
| 31:41 | with the sphere which is a three D . Shape | |
| 31:44 | we're about to learn and the circle the circle is | |
| 31:48 | flat but the sphere is three D . It's three | |
| 31:52 | Dimensional . All the shapes are like that . So | |
| 31:55 | let's learn all these three D shapes . So the | |
| 31:59 | first three D shape we're going to learn is the | |
| 32:02 | sphere . The one that we just mentioned . The | |
| 32:04 | sphere is the three D version of the circle . | |
| 32:09 | It's perfectly round . There are spheres all around us | |
| 32:16 | . One of the spheres we see all the time | |
| 32:18 | . Our balls like this soccer ball , a soccer | |
| 32:22 | ball is a sphere . It's perfectly round . It's | |
| 32:25 | a three D circle . It's a sphere . You | |
| 32:28 | know this fear ? Yes , it's the earth , | |
| 32:31 | it's where we live . Our planet is a sphere | |
| 32:35 | . How cool is that ? Our own planet is | |
| 32:38 | a sphere perfectly round . It's a sphere in this | |
| 32:44 | picture we have two spheres . Can you spot them | |
| 32:48 | ? Yeah , the two spheres are the two bullying | |
| 32:52 | balls . Perfect round spheres , spheres are all around | |
| 32:57 | us . Here we have a group of three spheres | |
| 33:02 | and you can count them right now . 123 spheres | |
| 33:07 | . All together the shape of a ball . A | |
| 33:09 | sphere perfectly round . Well there you have it . | |
| 33:15 | The sphere . What a cool three D shape to | |
| 33:18 | start with . Its round there . Examples all around | |
| 33:22 | us and it's just so cool and you know what | |
| 33:24 | ? The three D shapes are going to get even | |
| 33:27 | better . Our second three D shape is the cone | |
| 33:33 | . The cone is a really cool shape with a | |
| 33:35 | circle as the base or the bottom . And it | |
| 33:39 | all comes up to one point called a vertex . | |
| 33:43 | Here's an example of a cone . I think we | |
| 33:46 | all love the ice cream cone . If it doesn't | |
| 33:49 | have any ice cream inside and you flipped it upside | |
| 33:51 | down , you'd be able to see the circle base | |
| 33:53 | and it all comes up to one point called the | |
| 33:56 | vertex here are two cones , a red cone and | |
| 34:02 | a blue cone . And you can see both cones | |
| 34:05 | have that circle basin all comes up to a vertex | |
| 34:10 | . What wonderful cones have you seen these before ? | |
| 34:15 | Their traffic cones here are many cones . I didn't | |
| 34:20 | count all of them but there's a lot and they're | |
| 34:23 | wonderful wonderful cones . Yeah so that's our second three | |
| 34:29 | D shape . The kona wonderful cone with the great | |
| 34:33 | circle base . It all comes up to one point | |
| 34:36 | called the vertex . How awesome is that ? Our | |
| 34:42 | third three D shape is the pyramid . I love | |
| 34:44 | the pyramid . The pyramid is great . It comes | |
| 34:47 | up to one point just like the cone except the | |
| 34:49 | base is a square and the sides instead of being | |
| 34:52 | smooth . They are triangles . Okay , like these | |
| 34:58 | are awesome . These are so cool . The pyramids | |
| 35:02 | of Egypt , you see that they have the triangle | |
| 35:05 | sides and the bottoms of these pyramids are square . | |
| 35:09 | They're awesome . Examples of the pyramid . This is | |
| 35:12 | a pretty cool pyramid . It's a decoration that you | |
| 35:15 | plug into the wall , but it's a great example | |
| 35:18 | of what a pyramid looks like the bottom of the | |
| 35:20 | bases square . And there's the triangles on the sides | |
| 35:24 | . How cool is this ? Here's another pyramid and | |
| 35:29 | it's made of glass . There are so many decorations | |
| 35:33 | and things around . Maybe even your house that are | |
| 35:36 | shaped like a pyramid because pyramids look so cool . | |
| 35:39 | People love putting them everywhere . There you go . | |
| 35:42 | I mean you know the pyramid , it's a good | |
| 35:44 | shape . You know , you see a lot of | |
| 35:45 | them around , they've got the square bottom or base | |
| 35:49 | and the triangles on the sides and all goes up | |
| 35:52 | to a vertex . It's a classic shape . It's | |
| 35:55 | pretty awesome . Our 43D shape is the cylinder . | |
| 36:00 | Now , a cylinder is easy to spot because it's | |
| 36:03 | got a circle on the top and a circle on | |
| 36:05 | the bottom and it's smooth all around here , we | |
| 36:13 | have a can of soup and it's a cylinder has | |
| 36:16 | a circle on the top , a circle on the | |
| 36:19 | bottom and it's smooth all around all cans . And | |
| 36:23 | most jars are cylinders . Here we have three cylinders | |
| 36:28 | . Their candles . And can I tell you a | |
| 36:30 | secret ? Most candles are cylinders to right , Oh | |
| 36:36 | my God , this this is just too crazy and | |
| 36:39 | too awesome . Yeah , Here are two more cylinders | |
| 36:44 | . Are you kidding me ? Are you kidding me | |
| 36:46 | ? Even batteries are cylinders , cylinders are seriously everywhere | |
| 36:50 | . A circle on the top , a circle on | |
| 36:53 | the bottom and smooth all around . I mean really | |
| 36:57 | the cylinder is everywhere . I mean you know the | |
| 37:00 | circle on the top circle on the bottom smooth all | |
| 37:03 | around . I cylinder . Like what in the world | |
| 37:06 | do you have to be everywhere ? Okay , the | |
| 37:12 | next three D shape is the cube . The cube | |
| 37:15 | is the three D version of the square . It | |
| 37:18 | has six sides or faces that are all squares . | |
| 37:26 | Here we have two dice dice are in the shape | |
| 37:30 | of a cube . So these two dice or two | |
| 37:34 | cubes , they have six sides or faces that are | |
| 37:37 | all squares here we have many cubes . These are | |
| 37:44 | cubes that are made out of wood . Each of | |
| 37:47 | them have six sides or faces that are all squares | |
| 37:56 | . Here are seven cubes of ice . Have you | |
| 37:59 | ever had a warm drink and you need to put | |
| 38:01 | ice in it ? It's awesome because it has this | |
| 38:03 | great shape , the shape of a cube , six | |
| 38:08 | sides or faces . All squares . I mean there | |
| 38:11 | you go . The cube right ? The three D | |
| 38:15 | version of a square and it's got squares all along | |
| 38:19 | The sides right there . six sides or faces all | |
| 38:22 | squares . And I don't know . I think it's | |
| 38:24 | pretty cool shape . Our final three D shape is | |
| 38:30 | the rectangular prism . The rectangular prism is the three | |
| 38:34 | D version of the rectangle . It has six sides | |
| 38:38 | or faces that are all ready . Okay . An | |
| 38:41 | awesome example of the rectangular prism are bricks and here | |
| 38:45 | we have four bricks which are four rectangular prisms . | |
| 38:50 | The three D version of the Rectangle . You may | |
| 38:57 | have seen this in your classroom or in your home | |
| 39:00 | . It's a clean Xbox . And the clean Xbox | |
| 39:03 | is a great example of the rectangular prism . It's | |
| 39:06 | got six sides or faces that are all rectangles . | |
| 39:10 | Okay , so the secret is most boxes are rectangular | |
| 39:14 | prism . So here's another rectangular prism and it's a | |
| 39:18 | box and it's a shorter box but it still has | |
| 39:20 | rectangles all around . And it's rectangular prism . What | |
| 39:28 | else can we say ? It's a cool shape . | |
| 39:30 | The rectangular prism is the three D version of the | |
| 39:32 | rectangle . It has six sides or faces that are | |
| 39:35 | all rectangles . And it's just a neat shape to | |
| 39:39 | have around I think I mean you know . Okay | |
| 39:43 | so let's review pyramid cylinders . Okay . Mhm sphere | |
| 40:18 | . Mhm cylinder cones . Yeah . Yeah . Pyramid | |
| 40:41 | , rectangular prism . Yeah . Mhm spheres . Okay | |
| 40:53 | , let's do some more On the top . Here | |
| 40:59 | we have cubes . We can tell that because it's | |
| 41:03 | a 3D square . It has six sides or faces | |
| 41:07 | . Each of them are squares . Is pretty cool | |
| 41:10 | . Do you remember what shape these bricks are ? | |
| 41:14 | Yeah , a rectangular prism . They are rectangular prisms | |
| 41:18 | there , the 3D versions of the rectangle , mm | |
| 41:26 | at the top . We have a cone , a | |
| 41:30 | cone . It's got a circle base on the bottom | |
| 41:34 | and all comes up to one point called a vertex | |
| 41:39 | . Do you remember the shape here on the bottom | |
| 41:42 | ? These are three cylinders . They have a circle | |
| 41:46 | on the top and a circle on the bottom and | |
| 41:49 | it's smooth all around . You're doing such an awesome | |
| 41:57 | job . Seriously . So cool . So what's this | |
| 42:00 | top shape do you remember ? Yeah , it's a | |
| 42:03 | pyramid . A pyramid . A pyramid has a square | |
| 42:07 | base . It comes up to one vertex or one | |
| 42:10 | point and has triangles as the sides . All right | |
| 42:19 | . Do you remember this last shape here on the | |
| 42:21 | bottom ? Yes , it's the sphere . The sphere | |
| 42:25 | , which is the three D . Circle . And | |
| 42:27 | we started with it and we're ending with it and | |
| 42:30 | it's so awesome . Hey ? Well , okay , | |
| 42:35 | first of all elephants don't drive . Okay , elephants | |
| 42:39 | can't get a driver's license and he's driving on the | |
| 42:42 | grass . He's driving on the grass . You're gonna | |
| 42:45 | row in the lawn . Okay , let's go it | |
| 42:47 | on it . All right , This is out of | |
| 42:50 | hand . Okay , elephant , I don't want to | |
| 42:53 | tell you what you can do what you can't do | |
| 42:55 | what you can't drive . All right . Oh my | |
| 42:58 | goodness . All right . Next we are going to | |
| 43:01 | learn about roman numerals , which is a different way | |
| 43:05 | to write numbers . And it was used a long | |
| 43:08 | time ago in ancient Rome . And it's been used | |
| 43:11 | since then . And you can think of it almost | |
| 43:14 | as a secret code way of writing the numbers . | |
| 43:17 | It's pretty simple to learn . And we're going to | |
| 43:19 | go through that . The first roman numeral we're gonna | |
| 43:24 | learn is the roman numeral . I and I is | |
| 43:29 | one I equals one . So if you see an | |
| 43:34 | eye with the roman numeral , it's one the letter | |
| 43:37 | V . Is the roman numeral that means five . | |
| 43:41 | And the letter X . Is the roman numeral , | |
| 43:45 | that means 10 . So when you think one it's | |
| 43:50 | an eye , you think five it's a V . | |
| 43:53 | If you think 10 it's an X . So that's | |
| 43:59 | it just those three . I it almost looks like | |
| 44:04 | a one . That's how you can remember that . | |
| 44:06 | I is a one I . Is the roman numeral | |
| 44:09 | for one . A . V . Is in the | |
| 44:12 | number five . When you spell it out , the | |
| 44:14 | number five you see that right there . It has | |
| 44:16 | a V . In it . So when you think | |
| 44:18 | of V . You know oh you know what there's | |
| 44:21 | a V . In the spelled out number five . | |
| 44:26 | So the has to be five now . 10 is | |
| 44:29 | exit . We can't think of anything that could remind | |
| 44:33 | us of that . So there is no memorization thing | |
| 44:36 | just when you see the exits 10 and that's just | |
| 44:39 | what we're going to have to do . Okay one | |
| 44:43 | last time here , I just want to make sure | |
| 44:45 | you get it . There's only three . I is | |
| 44:47 | the roman numeral for one , the is the roman | |
| 44:51 | numeral for five and X is the roman numeral for | |
| 44:55 | 10 . And you've got to understand that so that | |
| 44:57 | we can start playing kind of a game of putting | |
| 45:00 | them together and making numbers Other than just 15 and | |
| 45:06 | 10 . So let's get started . So let's practice | |
| 45:11 | putting these Roman numerals together . What number do you | |
| 45:15 | think ? This is ? Two U . C . | |
| 45:20 | Two eyes two and i is one . So the | |
| 45:25 | answer is to two eyes is the number 21 What | |
| 45:35 | about this one ? You what number do you think | |
| 45:38 | ? This is ? Why there are three eyes ? | |
| 45:43 | Yeah it's the number three . Let's try this one | |
| 45:52 | . What number do you think this is ? We | |
| 45:57 | see two X . Is an X equals 10 . | |
| 46:02 | So 10 plus 10 equals 20 . Great job . | |
| 46:08 | This is the number 20 . Whoa . This one | |
| 46:16 | is so cool . Okay . X . And V | |
| 46:20 | . What number do you think ? This is the | |
| 46:26 | X . Is a 10 ? The V . Is | |
| 46:30 | what number five ? Awesome . So what is 10 | |
| 46:36 | plus five ? 15 . Whoa . Thanks so much | |
| 46:42 | for helping out now that we've looked at how to | |
| 46:47 | put some of these together . I want to tell | |
| 46:49 | you about two special numerals that are a little bit | |
| 46:52 | different . And so you're gonna have to just remember | |
| 46:55 | these on their own . The first is the number | |
| 46:58 | four and the number four is represented with an I | |
| 47:02 | . And V . And eyes before the V . | |
| 47:05 | Because four is one less than five which is V | |
| 47:09 | . So remember with four its I . V . | |
| 47:14 | With nine . It's similar except with the X . | |
| 47:17 | Nine is I . X . X . Is 10 | |
| 47:20 | . And eyes just before it . So nine is | |
| 47:24 | i . x . Okay . That was really cool | |
| 47:29 | . Thanks for hanging out and learning those with me | |
| 47:31 | . But we're not done . We want to go | |
| 47:33 | through all the numbers up to 30 just using the | |
| 47:38 | numerals and I want to see how much you've really | |
| 47:41 | learned . So if you'll do me a favor as | |
| 47:43 | the numerals go up , I want you to say | |
| 47:46 | the numbers along with me and we can practice together | |
| 47:50 | . Sound good . Alright , let's get started . | |
| 47:54 | Mhm . One two three four five . Sex seven | |
| 48:11 | eight nine , mm 10 11 , Yeah . 12 | |
| 48:21 | 13 , 14 , 15 , 16 , 17 , | |
| 48:33 | 18 , 19 , 20 21 22 23 24 , | |
| 48:45 | 25 26 , 27 28 29 and 30 . Mhm | |
| 48:56 | . Well there you have a new way to write | |
| 48:59 | numbers , wow , mom , you're doing such a | |
| 49:03 | great job in your race . I had no idea | |
| 49:06 | you were an athlete . Okay . I mean with | |
| 49:08 | all that cloth wrapped around , you're doing great . | |
| 49:11 | You're doing a great job . Just like these kids | |
| 49:13 | are doing a great job of learning . In fact | |
| 49:16 | , how about this ? The next thing we're gonna | |
| 49:18 | learn about is division . Division is such an awesome | |
| 49:25 | thing to be able to do . And you're going | |
| 49:27 | to have it all figured out . You're gonna learn | |
| 49:29 | how to divide . In this video . We're gonna | |
| 49:33 | start off with a story . There's this kid named | |
| 49:35 | Ethan and Ethan loves carrots . He loves carrots so | |
| 49:40 | much he loves to stack on him . He loves | |
| 49:43 | when he gets to eat them . They're crunchy . | |
| 49:45 | They're tasty . Yeah , carrots are awesome . In | |
| 49:50 | fact , I'm literally eating a carrot right now . | |
| 49:53 | As I'm speaking , carrots are great for your skin | |
| 49:56 | . Carrots are great for your eyes , they're amazing | |
| 49:58 | . You're a great snack . And Ethan loves them | |
| 50:03 | . Well Ethan has two friends over Kevin and Chloe | |
| 50:07 | and they start to get hungry . Mm Of course | |
| 50:12 | they all love carrots because carrots are like the perfect | |
| 50:16 | snack . Now in Ethan is house , there are | |
| 50:19 | only three carrots . They're just three carats . We | |
| 50:24 | are going to have to divide the three carats amongst | |
| 50:28 | the three kids . So let's figure this out . | |
| 50:31 | How many carats does each kid get ? Do you | |
| 50:35 | know ? Mm Uh huh . Each kid gets one | |
| 50:41 | carat pretty simple . Right ? Three carats . Three | |
| 50:45 | kids . Each kid gets one carrot . Mm Hey | |
| 50:50 | , did you know we just did division . Uh | |
| 50:53 | huh . We just did division . Mm Division is | |
| 50:57 | pretty simple . You see division is splitting a number | |
| 51:01 | up by any given number . That's it . Just | |
| 51:04 | splitting a number up . Let's look at our story | |
| 51:09 | again , There were three carrots . And we divided | |
| 51:12 | those three carats by three because there are three people | |
| 51:17 | , Right ? The three kids that love carrots . | |
| 51:20 | And the answer of how many carats each kid gets | |
| 51:24 | Is 1 , 3 divided by three equals 1 notice | |
| 51:33 | . Right ? Here is the division sign . This | |
| 51:36 | is what it looks like . When you see that | |
| 51:38 | sign , you could just say divided by So this | |
| 51:41 | reads three divided by three equals one . Let's try | |
| 51:47 | another example of division . Let's say there are eight | |
| 51:51 | presents , eight presents . And there are four women | |
| 51:55 | . And we want each of the women to get | |
| 51:57 | the same amount of presence as the other women . | |
| 52:00 | Because we want it to be fair notice the division | |
| 52:06 | sign we are going to divide or split up 8x4 | |
| 52:12 | . Remember to divide us to split up . Let's | |
| 52:16 | split these presents up into four equal groups . 1234 | |
| 52:23 | All right . How many presents does each woman get | |
| 52:28 | ? Uh huh . To each woman gets to presents | |
| 52:33 | . Mm . Yeah . Isn't that cool ? Division | |
| 52:37 | is so much fun . And it's so easy . | |
| 52:41 | Remember , division is splitting a number up by any | |
| 52:45 | given number . That's it . Mhm . All right | |
| 52:52 | . Now it's time for division facts . We're going | |
| 52:55 | to learn some pretty interesting facts about division . And | |
| 53:00 | you're gonna be like , oh my goodness . Like | |
| 53:03 | secrets . This is super cool . Okay , so | |
| 53:06 | just look around . All right , make sure . | |
| 53:09 | Right , who's clear are you ? It's time for | |
| 53:11 | division facts . The first fact is this You can | |
| 53:21 | never divide by zero . It's true . You can | |
| 53:24 | never divide by zero . Even if you're a rule | |
| 53:27 | breaker and you're like I'm gonna do whatever I want | |
| 53:30 | . You still can never divide by zero . In | |
| 53:33 | fact , if a teacher ever gives you a test | |
| 53:36 | and you see a problem where you have to divide | |
| 53:39 | a number by zero , just right on the test | |
| 53:42 | undefined because that's exactly what that answer would be undefined | |
| 53:47 | . It's impossible . Kind of like Mr Whiskers Math | |
| 53:52 | skills does Mr Whiskers do math in his head all | |
| 53:56 | day long . Who knows ? His Math skills are | |
| 53:59 | undefined ? We just don't know . It's impossible to | |
| 54:02 | know . You know Mr Whiskers might know how to | |
| 54:04 | do division . Who knows ? Undefined ? You can't | |
| 54:08 | divide by zero . You can never divide by zero | |
| 54:16 | . If you ever see any division problem dividing by | |
| 54:20 | zero , just right undefined . It's impossible . It's | |
| 54:24 | impossible . So just write undefined . The second fact | |
| 54:29 | is this , you can write the division sign three | |
| 54:35 | ways . Uh huh . Not just with that traditional | |
| 54:39 | division sign , you can write it like the division | |
| 54:42 | sign . Or you can write a division problem with | |
| 54:45 | the slash or with a horizontal line For example . | |
| 54:53 | Look at this 12 divided by three equals four . | |
| 54:56 | That's the original division sign . The one that you | |
| 54:59 | might see more regularly . Yeah . Yeah but here | |
| 55:05 | is the same equation written in a different way . | |
| 55:08 | 12 divided by three equals four . It's still a | |
| 55:12 | division sign but it's a slash . It means the | |
| 55:15 | same thing as the original division sign . Remember the | |
| 55:21 | division sign can also be a horizontal line . 12 | |
| 55:25 | divided by three equals four . That looks like a | |
| 55:28 | fraction , doesn't it ? The line in a fraction | |
| 55:31 | means divided by . These are the three ways that | |
| 55:39 | you can write the division sign . Pretty interesting . | |
| 55:44 | Okay . Alright . The final fact is this . | |
| 55:49 | Yeah . Okay . This is so awesome . You | |
| 55:53 | can flip the number of groups and the number in | |
| 55:56 | each group and the division problem stays true . For | |
| 56:01 | example 10 divided by two equals 5 . And you | |
| 56:05 | can flip the two and the five and it stays | |
| 56:08 | true . Yeah , that means 10 divided by five | |
| 56:15 | equals two . Isn't that interesting ? 10 divided by | |
| 56:18 | two equals five and 10 divided by five equals two | |
| 56:23 | . You can flip the number of groups and the | |
| 56:25 | number in each group and it still stays true . | |
| 56:29 | Or look at this 18 divided by six equals three | |
| 56:33 | . Remember we can flip the number of groups and | |
| 56:37 | the number in each group and it still stays true | |
| 56:40 | . So we could switch the six and the three | |
| 56:43 | and it stays true . Okay , so 18 divided | |
| 56:48 | by three equals six . The six and the three | |
| 56:51 | can be flipped . So 18 divided by six equals | |
| 56:55 | three and 18 divided by three equals six . Pretty | |
| 56:59 | nifty . Those were some cool facts . You know | |
| 57:03 | , division is a great time . Division is splitting | |
| 57:05 | a number up by any given number . It's a | |
| 57:09 | lot of fun . And we hope you learned a | |
| 57:11 | whole lot in this video . Wow . You completed | |
| 57:16 | the video . That is so impressive . Well , | |
| 57:19 | you might notice there's a circle right here on this | |
| 57:22 | video page that you can click to subscribe to our | |
| 57:25 | channel or you can click this rectangle to go to | |
| 57:28 | another one of our videos . But keep learning . | |
| 57:32 | Learning is so cool . |
Summarizer
DESCRIPTION:
2nd Grade math is fun with these learning videos! Each lesson can help students with word problems, math games or help prepare for a test! Great for a review of 2nd grade or for an introduction!
OVERVIEW:
2nd Grade Math Compilation is a free educational video by .
This page not only allows students and teachers view 2nd Grade Math Compilation videos but also find engaging Sample Questions, Apps, Pins, Worksheets, Books related to the following topics.
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