1. 3-9 Adding and Subtracting Mixed Numbers Do Now Add or subtract. 1. 2.
Course 2
3-9
Adding and Subtracting Mixed Numbers
Do Now
Add or subtract. 1. 2. 3. 4. 3 8 4 8 7 8 + 11 12 7 12 1 3 – 2 3 1 12 7 12 – 1 3 1 6 3 10 1 5 + –
Hwk:p 32 odd

2. 3-9 EQ: How do I add and subtract mixed numbers?
Course 2
3-9
Adding and Subtracting Mixed Numbers
EQ: How do I add and subtract mixed numbers?
M7N1.c Add, subtract, multiply, and divide positive and negative rational numbers;
M7N1.d Solve problems using rational numbers

3. Additional Example 1: Measurement Application
Course 2
3-9
Adding and Subtracting Mixed Numbers
Additional Example 1: Measurement Application 3 8 5 8
Kevin is 48 inches tall. His brother Keith is 5
inches taller. How tall is Keith ? 3 8 5 8 8 48 + 5 = 53 + =
53 + 1
54 inches tall.
A mixed number is the sum of an integer and a fraction: 3 =
Helpful Hint 4 5

4. Insert Lesson Title Here
Course 2
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Adding and Subtracting Mixed Numbers
Insert Lesson Title Here 2 3
Alvin weighs 72 lbs. His baby brother weighs lbs. How much do they weigh together? 1 3 1 3 2 3 + 15 72 =
Add the integers and add the fractions. 72 + 15 = 87 2 3 3 1 3 + 3 =
Rewrite
as 1.
Together they weigh 88 pounds.

5. 3-9 Adding and Subtracting Mixed Numbers 2 3 2 3 9 + 12 9 2 3 + 12 =
Course 2
3-9
Adding and Subtracting Mixed Numbers
Add. Write the answer in simplest form. 2 3 2 3 9 + 12 9 2 3 + 12 =
21 + 4 3 = 1 3 = 22 1 3

6. 3-9 Adding and Subtracting Mixed Numbers 1 8 5 6 5 + 3 = 5 + 3 = 8 +
Course 2
3-9
Adding and Subtracting Mixed Numbers
Add. Write the answer in simplest form. 1 8 5 6 5 + 3 = 20 24 3
= 8 + 23 24
Add the integers and add the fractions.
= 8 23 24
Add.

7. 3-9 Adding and Subtracting Mixed Numbers 7 + 10 7 4 5 + 10 2 = 17 + 6
Course 2
3-9
Adding and Subtracting Mixed Numbers
Check It Out: Example 2A
Add. Write the answer in simplest form. 4 5 2 5 7 + 10 7 4 5 + 10 2 =
17 + 6 5
Rewrite the improper fraction as a mixed number. = 1 5 = 18 1 5
Add.

8. 3-9 Adding and Subtracting Mixed Numbers 1 4 3 8 + 4 4 4 + 4 = 4 + 4
Course 2
3-9
Adding and Subtracting Mixed Numbers
Add. Write the answer in simplest form. 1 4 3 8 + 4 4 4 1
+ 4 3 8 = 3 8 2
= 8 + 5 8
Add the integers and add the fractions.
= 8 5 8
Add.

9. REGROUPING MIXED NUMBERS
Course 2
3-9
Adding and Subtracting Mixed Numbers
Sometimes when you subtract mixed numbers,
the fraction portion of the first number is less than
the fraction portion of the second number. In these
cases, you must regroup before subtracting.
REGROUPING MIXED NUMBERS
WORDS
NUMBERS
Regroup. 1 8 7 =
Rewrite 1 as a fraction with a common denominator. 8
= 6 + + 1
= 6 9 8
Add.

10. 3-9 Adding and Subtracting Mixed Numbers
Course 2
3-9
Adding and Subtracting Mixed Numbers
Remember!
Any fraction in which the numerator and denominator are the same is equal to 1.

11. Insert Lesson Title Here
Course 2
3-9
Adding and Subtracting Mixed Numbers
Insert Lesson Title Here
Subtract. Write the answer in simplest form. 2 3 1 3 4 – 2 4 2 3 – 1 =
2 + 1 3 = 2 1 3
Add.

12. Insert Lesson Title Here
Course 2
3-9
Adding and Subtracting Mixed Numbers
Insert Lesson Title Here
Subtract. Write the answer in simplest form. 8 9 2 3 12 – 8 12 8 9 – 2 3 = 12 8 9 – 6 =
4 + 2 9
Subtract integers and subtract fractions.
= 4 2 9
Add.

13. 3-9 Adding and Subtracting Mixed Numbers 1 8 3 8 17 – 12 16 9 8 – 12 3
Course 2
3-9
Adding and Subtracting Mixed Numbers
Subtract. Write the answer in simplest form. 1 8 3 8 17 – 12 16 9 8 – 12 3 17 1 8
– 12 = 3
Regroup 17 1 8
= 16+ + .
= 4 + 6 8
Subtract integers and
subtract fractions.
= 4 6 8 = 4 3
Add and simplify.

14. Insert Lesson Title Here
Course 2
3-9
Adding and Subtracting Mixed Numbers
Insert Lesson Title Here
Subtract. Write the answer in simplest form. 4 5 1 5 – 2 3 3 4 5 – 2 1 =
1 + 3 5
Subtract integers and subtract fractions. = 1 3 5
Add.

15. Insert Lesson Title Here
Course 2
3-9
Adding and Subtracting Mixed Numbers
Insert Lesson Title Here
Subtract. Write the answer in simplest form. 7 8 3 4 10 – 4 10 7 8 – 4 3 = 10 7 8 – 4 6
Find a common denominator. =
6 + 1 8
Subtract integers and subtract fractions.
= 6 1 8
Add.

16. 3-9 Adding and Subtracting Mixed Numbers 1 4 3 4 14 – 10 13 5 4 – 10 3
Course 2
3-9
Adding and Subtracting Mixed Numbers
Subtract. Write the answer in simplest form. 1 4 3 4 14 – 10 13 5 4 – 10 3 14 1 4
– 10 = 3
Regroup 14 1 4
= 13+ + .
= 3 + 2 4
Subtract integers and
subtract fractions.
= 3 2 4 = 3 1
Add and simplify.

17. Insert Lesson Title Here
Course 2
3-9
Adding and Subtracting Mixed Numbers
Insert Lesson Title Here
TOTD
Add or subtract. Write each answer in simplest form.
1. 5
2. 9
3. 7
4. 10 10 5 12 1 4 1 6 + 5 7 12 20 1 4 2 3
+ 10 7 8 3 4 5 1 8
– 2 2 9 5 6 5 7 18
– 4 1 2
5. A single roll of wallpaper unrolls to 15 yards 7 8
you hang 13 yards from the roll. How much
wallpaper remains?
1 yards 5 8