Mixed Number Subtraction With Regrouping!

Contributor: Stefani Allegretti. Lesson ID: 14178

Would you like to become mixed number super subtractor? Get ready to learn about a powerful strategy you can use when subtracting mixed numbers!

categories

Elementary, Fractions and Operations

subject
Math
learning style
Auditory, Visual
personality style
Otter, Golden Retriever
Grade Level
Intermediate (3-5)
Lesson Type
Quick Query

Lesson Plan - Get It!

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When subtracting mixed numbers, you subtract the whole number and the fraction separately.

Super simple!

However, sometimes this gets tricky.

Sometimes, the numerator on the top is smaller than the one you're subtracting, like in the example below.

fraction subtraction

 

  • So what can you do?

You can borrow from the whole number to make the smaller fraction bigger so subtracting is easier!

This is called regrouping, and it's a super strategy that helps make subtracting mixed numbers like this easier.

When your denominators are the same in a fraction, you can simply subtract the numerators.

In this example, however, you need to borrow from the whole number, 3, to make the numerator in the fraction 1/4 bigger.

4/4 is equal to 1 whole.

So, subtract one from 3.

Then, add 4 to the numerator 1.

fraction subtraction 2

So, the new mixed number becomes 2 5/4.

Now, it is super easy to subtract!

2 5 - 1 3 = 1 2
4 4 4

 

Next, simplify your fraction if necessary!

1 2/4 becomes 1 1/2.

There you go!

Now, check out this video to see the regrouping strategy in action!

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Great work!

To review, check out these simplified steps to follow when subtracting mixed numbers.

Step 1: Line up your problem vertically so the whole numbers are aligned and the fractions are aligned.

Step 2: Subtract the fractions.

Step 3: Borrow from the whole number if the numerator you are subtracting from is smaller than the numerator being subtracted.

Step 4: Add the fractional whole to the fraction you are subtracting from to make it bigger and reduce the whole number you borrowed from.

Step 4: Subtract the fractions and whole numbers.

Step 5: Reduce the fraction if necessary.

That's it!

Now try one more!

4 2 - 1 3 = ?
5 5

 

Follow the steps to solve the problem.

Click to check your answer below!

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Awesome work, mixed number super subtractor!

Now, head on over to the Got It? section for some more fun.

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