1. 5-4 Regrouping to Subtract Mixed Numbers Warm Up Problem of the Day
Course 1
Warm Up
Problem of the Day
Lesson Presentation

2. Warm Up Add or Subtract. 1. 3 + 1 2. 7 + 3. 8 – 2 4. 6 – 1 5 8 6 5 2 5
– – 1 2 5 __ 3 5 __ 9 11 __ 11 __ 9 11 __ 5 8 4 5 __ 1 4 __ 11 20 __ 1 3 __ 1 9 __ 2 9 __ 6 5

3. Jimmy and his family planted a tree when it was 1 ft
tall. Now the tree is ft tall. How much has the tree
grown since it was planted? 3 4 __ 1 1 4 __ 3
The difference in the heights can be represented by
2 – 1 4 __ 3
You will need to regroup because the fraction
in is greater than . 1 4 __
Divide one whole of into fourths.

4. The tree has grown ft since it was planted.1 4 __ 5 4 __ 2 1 1 4 1 4 __ 5 4 __
Regroup as 3 4 __ 3 4 __ –1
– 1
______ ______ 1 4 1 4 2 4 __ 1 2 __ = 1 2 __
The tree has grown ft since it was planted.

5. Additional Example 1A: Regrouping Mixed Numbers
Subtract. Write each answer in simplest form. 1 6 __ 5 6 __
– 2 1 6 __ 7 6 __ 1 6 __ 1 6 __ 6 __ 1 6 __ 7 6
Rename as = 5 6 __ 5 6 __
Subtract the fractions and then the whole numbers. –2 –2
______ ______ 2 6 __ 1 3 __ 4
Write the answer in simplest form.
= 4

6. Additional Example 1B: Regrouping Mixed Numbers
Subtract. Write each answer in simplest form. 2 5 __ 7 10 __
– 6 4 10 __ 14 10 __
10 is a multiple of 5, so 10 is a common denominator. 8 7 4 10 __ 7 10 __ 4 10 __ 10 __ 4 10 __ 7 10 __
Rename as = –6 –6
______ ______ 7 10 __
Subtract the fractions and then the whole numbers. 1

7. Additional Example 1C: Regrouping Mixed Numbers
Subtract. Write each answer in simplest form. 2 3 __
6 – 3 3 __
Write 6 as a mixed number with a denominator of 3. Rename 6 as 3 __ 6 5 2 3 __ 2 3 __
Subtract the fractions and then the whole numbers. –3 –3
______ ______ 1 3 __ 2

8. Additional Example 1D: Regrouping Mixed Numbers
Subtract. Write each answer in simplest form. 1 3 __ 3 4 __
– 2 4 12 __ 16 12 __ 5 4
The LCM of 4 and 3 is 12.
Rename as = 4 12 __ 9 12 __ 9 12 __ –2 –2
______ ______ 7 12 __
Subtract the fractions and then the whole numbers. 2

9. Check It Out: Example 1A Subtract. Write each answer in simplest form.8 __ 5 8 __
– 2 1 8 __ 9 8 __ 1 8 __ 1 8 __ 4 __ 1 8 __ 5 4
Rename as = 5 8 __ 5 8 __
Subtract the fractions and then the whole numbers. –2 –2
______ ______ 4 8 __ 1 2 __ 2
Write the answer in simplest form.
= 2

10. Check It Out: Example 1B Subtract. Write each answer in simplest form.6 __ 7 12 __
– 3 2 12 __ 14 12 __
12 is a multiple of 6, so 12 is a common denominator. 7 6 2 12 __ 2 12 __ 12 __ 7 12 __ 7 12 __ 2 12 __
Rename as = –3 –3
______ ______ 7 12 __
Subtract the fractions and then the whole numbers. 3

11. Check It Out: Example 1C Subtract. Write each answer in simplest form.3 4 __
5 – 2 4 __
Write 5 as a mixed number with a denominator of 4. Rename 5 as 5 4 4 __ 3 4 __ 3 4 __
Subtract the fractions and then the whole numbers. –2 –2
______ ______ 1 4 __ 2

12. Check It Out: Example 1D Subtract. Write each answer in simplest form.2 __ 2 3 __
– 4 3 6 __ 9 6 __ 8 7
The LCM of 2 and 3 is 6. 3 6 __ 4 6 __ 4 6 __ 3 6 __ 6 __ 3 6 __
Rename as = –4 –4
______ ______ 5 6 __
Subtract the fractions and then the whole numbers. 3

13. Additional Example 2A: Measurement Application
Li is making a quilt. She needs 15 yards of fabric.
Li has yards of fabric. How many more yards does she need? 3 4 __ 4 __
Write 15 as a mixed number with a denominator of 4. Rename 15 as 15 14 4 __ 3 4 __ 3 4 __ –2 –2
Subtract the fractions and then the whole numbers.
______ ______ 1 4 __ 12 1 4 __
Li needs another yards of fabric.

14. Additional Example 2B: Measurement Application
If Li uses yards of fabric, how much of the 15
yards will she have left? 1 6 __ 6 __
Write 15 as a mixed number with a denominator of 6. Rename 15 as 15 14 6 __ 1 6 __ 1 6 __
–11
–11
Subtract the fractions and then the whole numbers.
______ ______ 5 6 __ 3 5 6 __
Li will have 3 yards of fabric.

15. Check It Out: Example 2A
Peggy is making curtains. She needs 13 yards of fabric.
Peggy has yards of fabric. How many more yards does she need? 5 6 __ 6 __
Write 13 as a mixed number with a denominator of 6. Rename 13 as 13 12 6 __ 5 6 __ 5 6 __ –4 –4
Subtract the fractions and then the whole numbers.
______ ______ 1 6 __ 8 1 6 __
Peggy needs another yards of fabric.

16. Check It Out: Example 2B
If Peggy uses yards of fabric, how much of the 13
yards will she have left? 1 4 __ 4 __
Write 13 as a mixed number with a denominator of 4. Rename 13 as 13 12 4 __ 1 4 __ 1 4 __ –9 –9
Subtract the fractions and then the whole numbers.
______ ______ 3 4 __ 3 3 4 __
Peggy will have 3 yards of fabric left.

17. Lesson Quiz Subtract. Write each answer in simplest form.
– – 3
3. 7 – – 4
5. Irena put 10 cups of food in the bird feeder. The birds ate cups. How many cups are left? 7 10 __ 4 5 __ 4 9 10 __ 4 7 __ 6 7 __ 3 5 7 __ 2 9 __ 1 7 9 __ 3 8 __ 9 16 __ 5 13 16 __ 3 8 __ 5 8 __
6 cups