1. Warm Up
Problem of the Day
Lesson Presentation
Lesson Quizzes

2. Warm Up
Divide.
÷ 2
÷ 7
÷ 3
÷ 4
2.4
2.3
0.12
6.32

3. Problem of the Day
In the following magic square, is the product of the numbers in every row, column, and diagonal. Fill in the missing numbers.
4.5
0.25
0.5 3 1
1.5
2.25
0.75 9

4. Sunshine State Standards
MA.6.A.1.3 Solve real-world problems involving…division of…decimals.
Also MA.6.A.1.1, MA.6.A.1.2. MA.6.A.5.3

5. Multiplying the divisor and the dividend by the same number does not change the quotient.
42 ÷ 6 = 7
10  10
420 ÷ 60 = 7
  10
4,200 ÷ 600 = 7
Helpful Hint

6. Additional Example 1A: Dividing a Decimal by a Decimal
Find the quotient.
5.2 ÷ 1.3
Multiply the divisor by 101, or 10 to make it a whole number. Multiply the dividend by the same power of 10. 4
Think: 1.3 x 10 = x 10 = 52
13 52
Divide as with whole numbers.
–52
5.2 ÷ 1.3 = 4

7. Additional Example 1B: Dividing a Decimal by a Decimal
61.3 ÷ 0.36
Multiply the divisor by 102, or 100, to make it a whole number. Multiply the dividend by the same power of 10.
Think: 0.36 x 100 = x 100 = 6,130
36 6,

8. Additional Example 1B Continued7 .2 7 7
36 6,
Place the decimal point in the quotient. Divide as with whole numbers.
-36
253
-252 10 -0
When a repeating pattern occurs, show three dots or draw a bar over the repeating part of the quotient.
100
-72
280
-252
280
61.3 ÷ 0.36 = __
-252 28

9. Check It Out: Example 1
Find the quotient.
51.2 ÷ 0.25
204.8

10. Understand the Problem
Additional Example 2: Problem Solving Application
After driving miles, the Yorks filled up with 10.5 gallons of gas. On average, how many miles did they drive per gallon of gas? 1
Understand the Problem
The answer will be the average number of miles per gallon.
List the important information:
They drove miles. They used gallons of gas.

11. 2
Make a Plan
Solve a simpler problem by replacing the decimals in the problem with whole numbers.
If they drove 10 miles using 2 gallons of gas, they averaged 5 miles per gallon. You need to divide miles by gallons to solve the problem.
Solve 3
First estimate the answer. You can use compatible numbers.
216.3 ÷ ÷ 10 = 20

12. 3
Solve Continued
Multiply the divisor and dividend by 10. Think: 10.5 x 10 = x 10 = 2,163 2 .6
Place the decimal point in the quotient. Divide as with whole numbers.
-210 63 -0
630
-630
The York family averaged 20.6 miles per gallon.

13. Look Back 4
The answer is reasonable since 20.6 is close to the estimate of 20.

14. Understand the Problem
Check It Out: Example 2
After driving miles, the Changs filled up with 8.5 gallons of gas. On average, how many miles did they drive per gallon of gas? 1
Understand the Problem
The answer will be the average number of miles per gallon.
List the important information:
They drove miles. They used 8.5 gallons of gas.

15. 2
Make a Plan
Solve a simpler problem by replacing the decimals in the problem with whole numbers.
If they drove 10 miles using 2 gallons of gas, they averaged 5 miles per gallon. You need to divide miles by gallons to solve the problem.
Solve 3
8.5
154.7
The Chang family averaged 18.2 miles per gallon.

16. Look Back 4
Use compatible numbers to estimate the quotient.
154.7 ÷ 8.5 → 160 ÷ 8 = 20
The answer is reasonable because 18.2 is close to the estimate of 20.