Lumos Video Store
This page provides a list of educational videos related to First Subtraction. You can also use this page to find sample questions, apps, worksheets, lessons , infographics and presentations related to First Subtraction.
Subtraction within 20
By Khan Academy
Learn how to subtract 14 - 6 by first thinking about subtracting 2 and 4.
Mapping Diagrams | MathHelp.com
By MathHelp.com
This lesson covers subtracting decimals. Students learn to subtract decimals by first lining up the decimal points, then subtracting the numbers by column. For example, to subtract 9.514 -- 1.6, first line up the decimal points, then subtract the digits the thousandths column, to get 4 - 0, or 4, then subtract the digits in the hundredths column, to get 1 -- 0, or 1, then subtract the digits in units column, by borrowing a 1 from the 9 in the units column (which leaves an 8 in the units column), to get 15 -- 6, or 9, then subtract the digits in the units column, to get 8 -- 1, or 7. So 9.514 -- 1.6 = 7.914.
Multi-step word problem with decimals and subtraction
By Khan Academy
First visualize this word problem then use subtraction and multiplication of decimals and fractions to get at the answer.
Multi-step word problem with decimals and subtraction
By Khan,Academy
First visualize this word problem then use subtraction and multiplication of decimals and fractions to get at the answer.
Multi-step rational number word problems
By Khan Academy
First visualize this word problem then use subtraction and multiplication of decimals and fractions to get at the answer.
Adding and Subtracting Polynomials | MathHelp.com
By MathHelp.com
In this example, notice that each of our variables, x, y, and z, appears in all three equations. To solve this system, we use the addition method. In other words, let’s start with our first two equations, x + y + z = 4, and x – y + z = 2. Notice that if we add these equations together, the +y and –y will cancel out, and we have 2x + 2z = 6. So, in our new equation, 2x + 2z = 6, we’ve eliminated the variable y. Unfortunately, we still haven’t solved for any of our variables. However, if we can create another equation with just x and z in it, then we’ll have a system of equations in two variables, which we can use to solve for x and z. To create another equation with just x and z in it, we need to eliminate y. We can’t add the first and second equations together, because we’ve already done that. However, notice that if we add the first and third equations together, the first equation has a +y and the third equation has a –y, so we’ll be able to eliminate the y. So we have our first equation, x + y + z = 4, and our third equation, x – y – z = 0, and adding them together, notice that the +y – y cancels out, and, as a bonus, the +z – z also cancels out, so we have 2x = 4, and dividing both sides by 2, x = 2. Now, since we know that x = 2, notice that if we plug a 2 in for x in the equation that we created earlier, we can solve for z. And we have 2(2) + 2z = 6, or 4 + 2z = 6, and subtracting 4 from both sides, we have 2z = 2, and dividing both sides by 2, z = 1. So x = 2 and z = 1, and to find the value of y, we simply plug our values of x and z into any of the equations in the original system. Let’s use the first equation, x + y + z = 4. Since x = 2 and z = 1, we plug a 2 in for x and a 1 in for z, and we have 2 + y + 1 = 4, or 3 + y = 4, and subtracting 3 from both sides, y = 1. So x = 2, y = 1, and z = 1, and finally, we write our answer as the ordered triple, x, y, z, or (2, 1, 1).
Dividing Integers | MathHelp.com
By MathHelp.com
This lesson covers basic subtraction in the form of subtracting whole numbers. Students learn to subtract numbers with two or more digits, such as 985 - 47. The first step is to line up the numbers vertically so that the units digits are in the same column. Next, subtract the units digits, the tens digits, and the hundreds digits. When subtracting the units digits, notice that it is not possible to subtract 7 ones from 5 ones, so 1 ten must be borrowed from the tens column, leaving 7 tens and 15 ones. Now, subtracting the units digits, 15 - 7 = 8, subtracting the tens digits, 7 - 4 = 3, and subtracting the hundreds digits, 9 - 0 = 9. So 985 - 47 = 938. Note that the answer to a subtraction problem is called the difference, so the difference of 985 - 47 is 938.
Subtracting Mixed Numbers - YourTeacher.com - Pre Algebra Help
By yourteachermathhelp
For a complete lesson on subtracting mixed numbers go to http://www.yourteacher.com - 1000+ online math lessons featuring a personal math teacher inside every lesson! In this lesson students learn to subtract mixed numbers by first subtracting the fractions then subtracting the whole numbers. For example to subtract 6 1/3 - 4 2/3 first subtract 1/3 � 2/3. However notice that 1/3 � 2/3 equals a negative fraction. In this situation the first fraction 6 1/3 can be rewritten as 5 + 1 1/3 or 5 + 4/3 or 5 4/3. Therefore the original problem 6 1/3 - 4 2/3 can be rewritten as 5 4/3 - 4 2/3. Now subtract the fractions 4/3 � 2/3 to get 2/3 and subtract the whole numbers 5 �4 to get 1. So 5 4/3 - 4 2/3 = 1 2/3. Note that some of the problems in this lesson also require the student to find a common denominator for the fractions. For example 8 5/16 - 1 1/8.
Adding and Subtracting Vectors Part1.avi - YouTube
By AlRichards314
This lesson shows how to add and subtract geometric vectors. This is the first part of a two part lesson. This lesson was created for the Calculus and Vectors (MCV4U) course in the province of Ontario, Canada.
Quadratic Word Problems | MathHelp.com
By MathHelp.com
A number is 56 less than its square. Find the number. To solve this problem, let’s translate the first sentence into an equation. A number, that’s x, is, =, 56 less than it’s square, that’s x squared – 56. Remember that “less than” switches the order around. In other words, “56 less than its square” is not 56 minus x squared, it’s x squared minus 56. Next, since we have an x squared term in our equation, we set it equal to 0 by subtracting x from both sides, and we have 0 = x squared – x – 56. Next, we factor the right side as the product of two binomials. In the first position of each binomial, we have the factors of x squared, x and x. In the second position of each binomial, we’re looking for the factors of -56 that add to -1, which are -8 and positive 7. So we have 0 = x - 8 times x + 7, which means that either 0 = x – 8 or 0 = x + 7. Finally, in the first equation, we add 8 to both sides, to get 8 = x. And in the second equation, we subtract 7 from both sides, to get -7 = x. So 8 = x or -7 = x. It’s important to understand that both of these answers work. Plugging an 8 back into the original problem, we have 8 is 56 less than 8 squared, or 8 = 8 squared – 56, which simplifies to 8 = 64 – 56, or 8 = 8, which is a true statement. And plugging a -7 back into the original problem, we have -7 is 56 less than -7 squared, or -7 = -7 squared – 56, which simplifies to -7 = 49 – 56, or -7 = -7, which is also a true statement.
Adding and Subtracting Feet and Inches
By eHow
Teacher works at the chalk board to show how to use conversion to subtract feet and inches. Add feet measures first and then add the inches. If the inches equal more than 12 inches student must convert the inches to feet. Video is captioned. The instructor Alex Martinez is a mechanical engineering student at the University of Massachusetts at Amherst.
Composite Functions: f(g(x)) and g(f(x)) | MathHelp.com
By MathHelp.com
In this problem, we’re asked to add the given polynomials, then we’re asked to subtract the second polynomial from the first. In part a, to add the given polynomials, we simply add parentheses t^2 + 6t – 9 + parentheses t^2 + 7t - 3. Notice that I used parentheses around the polynomials. This is a good habit to get into, even though the parentheses will not affect the addition. Next, we simply add the like terms, t^2 + t^2 is 2t^2, 6t + 7t is 13t, and -9 - 3 is -12. So we have 2t^2 + 13t – 12. In part b, we’re asked to subtract the second polynomial from the first, so we have parentheses t^2 + 6t – 9 minus parentheses t^2 + 7t - 3. Notice that the second polynomial is subtracted from the first. And again, notice that we use parentheses around each polynomial. Now, it’s important to understand that the minus sign outside the second set of parentheses can be thought of as a negative 1, so we need to distribute the -1 through each of the terms in the second set of parentheses. So, after rewriting our first polynomial, t^2 + 6t – 9, we have -1 times t^2, or –t^2, -1 times positive 7t, which is -7t, and -1 times -3, which is positive 3. Now, we combine like terms. t^2 – t^2 cancels out, positive 6t minus 7t is -1t, or –t, and -9 + 3 is -6. So we have –t – 6. Makes sure to distribute the negative 1 through the parentheses when subtracting the second polynomial from the first.
01 - Learn Order Of Operations (5th Grade Math)
By Lumos Learning
This is just a few minutes of a complete course. Get all lessons & more subjects at: http://www.MathTutorDVD.com. This lesson teaches how to use the rules of order of operations to solve problems.
The Steps to Long Division
By TheAnimatedClassroom
Here in this cartoon Whale helps out Clam with an easy way to remember the steps to long division. Remember the first letter of Daddy Mother Sister Brother. Step 1-Divide Step 2-Multiply Step 3-Subtract Step 4-Bring Down.Then repeat the steps. This is a great resource to introduce and/or review division in the classroom and at home.
One-Step Addition Equations | MathHelp.com
By MathHelp.com
This lesson covers number patterns. Students learn to find the next 3 terms in advanced patterns that involve figures, letters, or numbers. For example, to find the next three terms in the pattern A, Z, B, Y, __, __, __, notice that the first and third terms in the pattern, A and B, are the first two letters in the alphabet, so the fifth and seventh terms in the pattern will be the next two letters in the alphabet, C and D. And the second and fourth terms in the pattern, Z and Y, are the last letter and the second-to-last letter in the alphabet, so the sixth term in the pattern will be the third-to-last letter in the alphabet, X. So the next three terms in the pattern A, Z, B, Y, __, __, __ are C, X, and D.
Master the Order of Operations (PEMDAS) in Math - [5-7-5]
By Math and Science
Quality Math And Science Videos that feature step-by-step example problems!
