Adding and Subtracting Mixed Numbers

Rate this video

Be the first to rate this video!

The author
Avatar
Team Digital
Adding and Subtracting Mixed Numbers
CCSS.MATH.CONTENT.4.NF.B.3.C CCSS.MATH.CONTENT.4.NF.B.3.D

Information about the video Adding and Subtracting Mixed Numbers

Contents

  • How do you add and subtract mixed numbers?
  • How do you add and subtract mixed numbers?

    Axel and Tank find a recipe, but they cannot tell what the title says. In order to figure out what the recipe makes, they need to practice adding and subtracting mixed numbers so they know how much of each ingredient to use.

    Steps to Adding and Subtracting Mixed Numbers

    When you practice adding and subtracting mixed numbers with like denominators, you can follow these three steps:

    • Step One: Add or subtract the whole numbers.
    • Step Two: Add or subtract the fractions.
    • Step Three: Simplify your answer if you need to.

    Adding and Subtracting Mixed Numbers Examples

    Let’s start by adding three and two-eighths and four and five-eighths.

    three-and-two-eighths-plus-four-and-five-eighths-adding-and-subtracting-mixed-numbers.svg

    First, we need to find the sum of the whole numbers. That means, we are adding three and four first to get the sum seven.

    Next, we find the sum of the fractions. Remember, when adding and subtracting fractions with common denominators we simply add or subtract the numerators and the denominators stay the same. Two-eighths plus five-eighths equals seven-eights.

    three-and-two-eighths-plus-four-and-five-eighths-equals-seven-and-seven-eighths-adding-and-subtracting-mixed-numbers.svg

    Our last step is to simplify our answer if we need to. A fraction is in simplest form when the numerator and denominator have no common factors other than one. Since seven and seven-eighths is in simplest form we can skip this step.

    Now let’s practice subtracting mixed numbers by calculating five and three-fourths minus four and one-fourth.

    five-and-three-fourths-minus-four-and-one-fourth-adding-and-subtracting-mixed-numbers.svg

    First, we need to find the difference of the whole numbers. That means, we are subtracting five and four first to get the difference of one.

    Next, we find the difference of the fractions. Three-fourths minus one-fourth equals two-fourths.

    five-and-three-fourths-minus-four-and-one-fourth-equals-one-and-two-fourths-adding-and-subtracting-mixed-numbers.svg

    Our last step is to simplify our answer if we need to. The numerator and the denominator have the common factor of two, which means it can be simplified to one-half.

    one-and-one-half-adding-and-subtracting-mixed-numbers-with-like-denominators.svg

    How to Add and Subtract Mixed Numbers Summary

    Remember, when you add and subtract mixed numbers with like denominators, you can follow these three steps:

    • Step One: Add or subtract the whole numbers.
    • Step Two: Add or subtract the fractions.
    • Step Three: Simplify your answer if you need to.

Transcript Adding and Subtracting Mixed Numbers

Axel and Tank are having a lazy day. Tank decides he wants to read a book, but what is this? [curious/surprised] Looks like some kind of recipe...very mysterious! In order to figure out what the recipe makes, Tank and Axel need to... [title] "add and subtract mixed numbers" so they know how much of each ingredient to use. A mixed number is a combination of a whole number and a fraction. We can add or subtract mixed numbers using three steps. The first step is to add or subtract the whole numbers. The second step is to add or subtract the fractions. The third step is to simplify your answer if you need to. Let's see how many containers of glue Axel and Tank need. In order to do that, we need to ADD three and two-eighths and four and five-eighths. First, we need to find the sum of the whole numbers. That means, we are adding three (...) and four first...what is the sum of three PLUS four? (...) The sum of three and four is seven. Next, we find the sum of the fractions. Remember, when we add or subtract fractions with COMMON denominators... we simply add or subtract the NUMERATORS (...) and the DENOMINATORS stay the same Two-eighths (...) plus five-eighths equals (...) seven-eights. Our last step is to simplify our answer if we need to. A fraction is in simplest form when the numerator and denominator have no common factors other than one. This is true for the fraction seven-eighths, so they need "seven and seven-eighths" containers of glue. Now, let's help them calculate how many containers of baking soda they need. In order to do that, we need to SUBTRACT "five and three-fourths and four and one-fourth". First, we need to find the difference of the whole numbers. So, what is the difference of the whole numbers when you subtract? When we subtract the whole numbers five (...) and four(...) the difference is (...) "one". Next, we subtract the fractions. What is the difference of the fractions three-fourths (...) and one-fourth? Since the denominators stay the same, we only subtract three MINUS one. Three MINUS one is two which gives us the final answer "two-fourths". Our last step is to simplify our answer if we need to. Can we simplify the fraction two-fourths?

The numerator and the denominator have the common factor of two, which means it CAN be simplified to "one-half". Axel and Tank need one and one-half containers of baking soda for the recipe. Lastly, let's help them calculate how many containers of contact lens solution they need. In order to do that, we need to ADD "one and one-third (...) and two and two-thirds". First, can you find the sum of the whole numbers by adding? The sum of one (...) plus two(...) is "three". Next, we add the fractions. What is the sum of the fractions? The sum of one-third(...) plus two thirds(...) is "three-thirds". Our last step is to simplify our answer if we need to. Can we simplify the fraction three-thirds? Since we have all three parts of our whole(...)we can rewrite three-thirds as one whole. Now we add three PLUS one which gives us "four". Axel and Tank need four containers of contact lens solution for the recipe. Remember (...), you can add or subtract mixed numbers with common denominators by following three steps. The first step is to "add or subtract the whole numbers". The second step is to "add or subtract the fractions". The third step is to "simplify your answer if you need to". Luckily, Axel and Tank had enough of each ingredient on hand. Let's see how the recipe turned out!