Mixed numbers consist of a whole number portion and a fraction portion. In the mixed number 4 1/8, 4 is the whole number and 1/8 is the fraction. There are times when subtracting mixed numbers that you will be required to regroup. This is an easy process, if you just think about the meaning behind the steps it will all make sense.

## Subtract Mixed Numbers with Regrouping

Look at the denominators in the fractions being subtracted. If the denominators are different, rewrite the fractions so they have like denominators. For example, in 4 1/8 - 3 1/4, the lowest common denominators of 8 and 4 is 8. The mixed number 4 1/8 would not change. The fractional part of 3 1/4 would change.

3 1/4= 3 + 1/4 x ?/?=?/8

Since 8 is the lowest common denominator you'd ask yourself what do I multiply 4 by to get 8? The answer is 2. Whatever you do to the denominator you also do to the numerator so 1 x 2 = 2, so the new mixed number is 3 2/8.

Now your problem looks like this 4 1/8 - 3 2/8=?

Decide if you need to regroup. In this problem 1/8 - 2/8 is not possible because 1/8 is bigger than 2/8. You need to regroup.

4 1/8 = 3 + 8/8 + 1/8 = 3 9/8

To make the 1/8 larger, you are going to borrow 1 from the whole number 4. The 1 you are borrowing from 4 is the same as borrowing 8/8. The 4 becomes a 3 and you add the 8/8 to the 1/8 leaving you with 3 9/8.

Now your problem looks like this 3 9/8 - 3 2/8 = ?

Subtract the fractions.

9/8 - 2/8 = 7/8

Subtract the whole numbers.

3 - 3 = 0

Write the difference in simplest form.

7/8 is already in simplest form.