1. Warm Up – Get Your Clicker Please
Lesson Presentation
Lesson Quizzes

2. Add or subtract. Write each answer in simplest form.
Warm Up
Add or subtract. Write each answer in simplest form. 1 12 __ 31 33 __ 11 12 __ 7 12 __

3. Learn to add and subtract mixed numbers with unlike denominators.

4. Additional Example 1A: Adding and Subtracting Mixed Numbers
Find the sum. Write the answer in simplest form. 1 8 __ 5 6 __
3 + 2 = 5
Estimate the sum. 1 8 __ 6 48 __
Multiply the denominators · 6 = 48 3 3 5 6 __ 40 48 __
Write equivalent fractions with a denominator of 48. +1
+ 1
______ ______
Add the fractions and then whole numbers, and simplify. 46 48 __ 23 24 __
= 4
4 is close to the estimate of 5. The answer is reasonable. 46 48 __

5. Additional Example 1B: Adding and Subtracting Mixed Numbers
Find the difference. Write the answer in simplest form. 2 3 __ 1 4 __
5 – 1
6 – 1 = 5
Estimate the difference. 2 3 __ 8 12 __
The LCD of 3 and 4 is 12. 5 5 1 4 __ 3 12 __
Write equivalent fractions with a denominator of 12. –1
– 1
______ ______ 5 12 __
Subtract the fractions and then the whole numbers. 4 5 12 __
4 is close to the estimate 5. The answer is reasonable.

6. Additional Example 1C: Adding and Subtracting Mixed Numbers
Find the difference. Write the answer in simplest form. 2 3 __ 2 9 __
6 – 3
7 – 3 = 4
Estimate the difference. 2 3 __ 6 9 __
Think: 9 is a multiple of 3, so 9 is the LCD. 6 6 2 9 __ 2 9 __
Write equivalent fractions with a denominator of 9. –3
– 3
______ ______ 4 9 __ 3
Subtract the fractions and then the whole numbers. 4 9 __
3 is close to the estimate 4. The answer is reasonable.

7. Check It Out: Example 1A
Find the sum. Write the answer in simplest form. 1 4 __ 1 6 __
2 + 3 = 5
Estimate the sum. 1 4 __ 6 24 __
Multiply the denominators · 6 = 24 2 2 1 6 __ 4 24 __
Write equivalent fractions with a denominator of 24. +3
+ 3
______ ______ 10 24 __ 5 12 __
Add the fractions and then whole numbers, and simplify.
= 5 5 12 __
5 is close to the estimate 5. The answer is reasonable.

8. Check It Out: Example 1B
Find the difference. Write the answer in simplest form. 1 2 __ 3 7 __
– 1
5 – 2 = 3
Estimate the difference. 1 2 __ 7 14 __ 4 4
The LCD of 2 and 7 is 14. 3 7 __ 6 14 __
Write equivalent fractions with a denominator of 14. –1
– 1
______ ______ 1 14 __
Subtract the fractions and then the whole numbers. 3 1 14 __
3 is close to the estimate 3. The answer is reasonable.

9. Check It Out: Example 1C
Find the difference. Write the answer in simplest form. 3 4 __ 1 8 __
– 2
8 – 2 = 6
Estimate the difference.
Think: 8 is a multiple of 4, so 8 is the LCD. 3 4 __ 6 8 __ 7 7
Write equivalent fractions with a denominator of 8. 1 8 __ 1 8 __ –2
– 2
______ ______ 5 8 __
Subtract the fractions and then the whole numbers. 5 5 8 __
5 is close to the estimate 6. The answer is reasonable.

10. Additional Example 2: Measurement Application
The length of Jen’s kitten’s body is inches. Its tail is 5
inches long. What is the total length of its body and tail? 1 4 __ 1 8 __ 1 4 __ 8
Add
Find a common denominator. Write equivalent fractions with the LCD, 8, as the denominator. 1 4 __ 2 8 __ 10 10 1 8 __ 1 8 __ +5
+ 5
______ ______
Add the fractions and then the whole numbers. 3 8 __ 15 3 8 __
The total length of the kitten’s body and tail is inches.
You can use mental math to find an LCD. Think: 8 is a multiple of 4 and 8.
Helpful Hint

11. Check It Out: Example 2
The length of Regina’s mouse’s body is inches. Its tail is 2
inches long. What is the total length of its body and tail? 2 3 __ 1 6 __ 2 3 __ 1 6
Add
Find a common denominator. Write equivalent fractions with the LCD, 6, as the denominator. 2 3 __ 4 6 __ 2 2 1 6 __ 1 6 __ +2
+ 2
______ ______ 5 6 __
Add the fractions and then the whole numbers. 4 5 6 __
The total length of the mouse’s body and tail is inches.

12. Lesson Quizzes
Standard Lesson Quiz
Lesson Quiz for Student Response Systems

13. Lesson Quiz
Find each sum or difference. Write the answer in simplest form.
5. Miles worked hours on Friday and hours on
Saturday. How many total hours did he work? 3 1 4 __ 16 13 24 __ 8 7 40 __ 6 7 30 __ 3 __ __ 2 4 3 5 12 __
14 hours

14. Lesson Quiz for Student Response Systems
1. Identify the difference in the simplest form.
A C.
B D.

15. Lesson Quiz for Student Response Systems
2. Identify the sum in the simplest form.
A C.
B D.

16. Lesson Quiz for Student Response Systems
3. Identify the sum in the simplest form.
A C.
B D.

17. Lesson Quiz for Student Response Systems
4. Identify the difference in the simplest form.
A C.
B D.

18. Lesson Quiz for Student Response Systems
5. Shiloh bought pounds of bananas and pounds of apples. How many pounds of fruits did she buy?
A C.
B D.