Fractions - By tecmath
Transcript
00:0-1 | today in this video we're going to be doing is | |
00:02 | we're going to do something to look at the basics | |
00:03 | of fractions , fractions numbers which are used to describe | |
00:08 | parts of a whole and you'll often see them written | |
00:11 | as follows . I'll write one down right now , | |
00:14 | three quarters a common fraction . But I'll just go | |
00:17 | through to explain the different parts of the different names | |
00:20 | of what we have when we talk about fractions . | |
00:22 | So first off we have the number up the top | |
00:25 | here and the top number is called the numerator and | |
00:29 | I'll just write that down . Okay , so this | |
00:31 | is called the numerator . The bottom number here is | |
00:35 | called the denominator , the deer nominator . And you'll | |
00:40 | quite often hear people refer to the lowest common denominator | |
00:43 | and things like this . Okay , so we often | |
00:46 | just think of this as top number and bottom number | |
00:48 | , but it's a numerator and the denominator , the | |
00:51 | other part of a fraction that we have here is | |
00:54 | this part here , which is this line here . | |
00:56 | Okay . And this line is called the vin column | |
01:00 | and I know I am going to say that incorrectly | |
01:02 | , the vin column . So just say it twice | |
01:05 | just to really reinforce the incorrect way of probably saying | |
01:08 | it . So often when I think about this middle | |
01:11 | part here , I think about this being divide . | |
01:13 | So I'll show you what I really mean by this | |
01:15 | . When I talk about this , When I think | |
01:17 | about fractions , I think about them being either three | |
01:20 | parts of four or three out of four . But | |
01:23 | if I'm thinking about this sometimes the numbers , I | |
01:24 | also think this has three divided by four and I | |
01:27 | think that's a great way to think about it as | |
01:29 | well . And that helps you if you get stuck | |
01:32 | on fractions because you can work out what the decimal | |
01:35 | of these are just by going three divided by four | |
01:38 | , which is equal to 0.75 . Then further from | |
01:42 | this you can see the relationship to percentage because this | |
01:45 | number is out of one . But if we multiply | |
01:47 | by 100 just to make it a little bit nicer | |
01:49 | , we end up with the percentage which is 75 | |
01:53 | percent . So what types of fractions do we have | |
01:57 | now ? I guess the proper fraction is what you | |
01:59 | think of as a normal fraction ? Where we have | |
02:01 | the numerator , the top number being bigger than the | |
02:04 | denominator . So the number we have before three quarters | |
02:07 | was an example of a proper fraction . The numerator | |
02:11 | is bigger than the denominator half would be an example | |
02:15 | of a proper fraction or say something like three fits | |
02:19 | . Okay , these are all examples of proper fractions | |
02:22 | . The numerator is bigger than the denominator . How | |
02:25 | we have another type of fraction which is important to | |
02:27 | know which is called an improper fraction . So improper | |
02:31 | fractions as opposed to proper fractions are fractions where our | |
02:34 | denominator is bigger than our numerator . An example for | |
02:38 | this might be for over three . Okay , four | |
02:41 | out of three . And you might think that's a | |
02:43 | bit counterintuitive . How can you have a bigger number | |
02:45 | out of a smaller number and we'll have a look | |
02:48 | at that in a little bit lighter . Okay . | |
02:50 | Or you might have something like five out of two | |
02:53 | . Any time that you have this numerator bigger than | |
02:56 | the denominator , you have yourself an improper fraction . | |
02:59 | Now we can change an improper fraction too what's known | |
03:03 | as a mixed number . So this leads us to | |
03:06 | another type of fraction which is a mixed number . | |
03:09 | A mixed number is where you have a mixture between | |
03:11 | whole numbers and fractions . Okay , so four out | |
03:15 | of three as a mixed number and I'm gonna show | |
03:17 | you at a different stage how to work this out | |
03:18 | . And they're pretty easy , would be written as | |
03:21 | one and one third or 5/2 Could be written as | |
03:25 | 2.5 . Okay . We have an improper fraction which | |
03:30 | can be converted across to a mixed number . So | |
03:33 | just to explain all those different ideas we've gone through | |
03:36 | and how they relate to one another . What about | |
03:38 | I show you on a number line so that this | |
03:41 | number line and it's going along it's gonna start at | |
03:43 | zero . We go along one part , We go | |
03:47 | along another 2 , 2 . We don't need to | |
03:50 | actually go any further to show you what I want | |
03:52 | to show you here . So say let's consider the | |
03:55 | fraction three quarters . Now at the moment this is | |
03:57 | in an improper fraction form . Okay , the numerator | |
04:01 | is bigger than the denominator . So let's actually put | |
04:04 | this on the number line . How do we go | |
04:06 | about doing this between 10 here , divide up this | |
04:10 | many times the amount which is the denominator . So | |
04:13 | we're going to break up between one and zero here | |
04:15 | four times four . Equal parts 1234 We could keep | |
04:19 | going and keep doing it here as well . 1234 | |
04:22 | So we can do now is we can go through | |
04:23 | and start putting fractions along our number line here . | |
04:26 | All related to quarters , we could go along one | |
04:28 | part And we have gone one out of four Where | |
04:31 | you go along to party and we're going to out | |
04:34 | of four . We go along another one and we've | |
04:36 | gone three parts out of four . And you're gonna | |
04:38 | see this is the one we wanted to put on | |
04:41 | gonna rub it out because I'm going to keep going | |
04:42 | with this idea here , we've gone four out of | |
04:45 | four . And as I said before , you can | |
04:46 | go , hey , that's 14 out of four is | |
04:48 | equal to 14 divided by four is equal to one | |
04:52 | . Like we said before , we have five out | |
04:55 | of four , we can keep going . We have | |
04:57 | six out of four . We have seven out of | |
05:00 | four . We could go eight out of four . | |
05:02 | Once again , eight divided by four is equal to | |
05:05 | two . All right . So what do we got | |
05:07 | so far ? You can see what we have here | |
05:09 | is a whole bunch of proper fractions . We go | |
05:13 | here and we have a whole bunch of improper fractions | |
05:17 | . So what we could also do is we could | |
05:19 | change all these guys here across to mixed numbers . | |
05:23 | Okay , Because five divided by four is one and | |
05:27 | one left over one out of four . Okay , | |
05:29 | this is one plus one quarter . Okay , so | |
05:32 | one and a quarter , this is one and two | |
05:36 | quarters , this is one and three quarters , so | |
05:39 | we'll put that one in there and I'll put this | |
05:40 | one in here because that fits as well . This | |
05:42 | is one and three quarters and seven divided by four | |
05:45 | is one with three left over 3/4 . That's pretty | |
05:49 | all right , not too bad . Just leave that | |
05:51 | last thing I want to explain which is I guess | |
05:54 | equivalent fractions . Now , what we also could have | |
05:57 | done is we could have got our number line here | |
05:59 | instead of breaking up before I could have considered halves | |
06:03 | . Now I want to leave this all up here | |
06:05 | because I just want to use it to explain something | |
06:08 | and that is equivalent fractions . So if I was | |
06:10 | to break this up into halves , I start with | |
06:12 | my zero and I would have broken it up like | |
06:14 | this , they can't be breaking it up in two | |
06:16 | halves . Okay , one , there has been halved | |
06:19 | into two equal parts and this part here has been | |
06:21 | halved in technical parts . Now if I was going | |
06:24 | up like this , what you'd see is I'd go | |
06:26 | up one out of two , I would have gone | |
06:28 | up two out of 23 out of 24 out of | |
06:31 | two , but it's just these parts here that I | |
06:33 | want to show you what we have is equivalent fractions | |
06:36 | here . two is twice as big as one and | |
06:39 | four is twice as big as two anyway , hopefully | |
06:44 | that was a great introduction for our fractions for you | |
06:47 | . We'll see you next time . Bye . |
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Fractions is a free educational video by tecmath.
This page not only allows students and teachers view Fractions videos but also find engaging Sample Questions, Apps, Pins, Worksheets, Books related to the following topics.