Check Your Understanding Lesson 1-3 ACTIVITY 1

Lesson 1-3
Multiplying Decimals
ACTIVITY 1
continued
My Notes
Check Your Understanding
13. Model with mathematics. Use a decimal model to find the
product. Model the first factor by shading columns and the second
factor by shading rows.
a. 0.4 × 0.6
b. 0.6 × 0.4
c. What property of multiplication do your answers to Parts a and
b illustrate? Explain.
14. Find the product.
a. 6.7 × 4.2
d. 0.045 × 10,000
b. 5.77 × 0.6
e. 0.0071 × 0.34
c. 9.23 × 17
f. 12.15 × 5.2
LESSON 1-3 PRACTICE
15. Damon works 32 hours per week and earns $10.75 per hour.
a. Estimate his weekly earnings. Explain how you determined
your estimate.
b. Find the exact amount he earns per week.
c. Is your answer reasonable based on your estimate? Explain.
MATH TIP
To find the area of a rectangle,
multiply the length and the width.
17. A rectangular soccer field is 70.75 meters wide and 105.25 meters
long.
a. Estimate the area of the field.
b. Find the area of the field. Round your answer to the nearest
hundredth.
18. On the morning of a business trip, Maria drove for 3.1 hours at an
average rate of 63.8 miles per hour. In the afternoon, she drove for
3.5 hours at an average rate of 59.5 miles per hour.
a. Did she travel farther in the morning or the afternoon?
b. How much farther did she travel?
19. Reason abstractly. Can the product of a whole number and a
decimal number less than 1 ever be greater than the whole
number? Give examples to support your answer.
20. a. Describe two ways to find the product 4.2(6 + 0.43).
b. What property of multiplication does your answer to Part a
illustrate?
14
Unit 1 • Number Concepts
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16. a. Lyla wants to model 3 × 0.17 on a 10-by-10 grid. Show how she
might do this.
b. What is the product?