Multiplying decimals by the powers of 10
Estimate the product
Use models to multiply
Multiple a decimal and whole number
100
63.7 x 10
637
100
37 x 0.93
37
100
5 x 0.5
2.5
100
56 x 0.4
22.4
200
5.02 x 100
502
200
3.2 x 184
600
200
100 x 0.12
12
200
5.8 × 11
63.8
300
0.365 x 104
3,650
300
45.3 x 4
180
300
Jen bought 3.72 pounds of apples at afarmer’s market. Andrea bought 4 times asmuch as Jen.
Which expression represents the problem?
3.72 x 4
300
Derrick runs 2.25 miles each day. How many total miles will he have run after 10 days? Explain.
22.5 Miles; I moved the decimal point in 2.25 one place to the right
400
681.7 x 105
68,170,000
400
99.2 x 82
8,000
400
Nadia drew a square in her notebook. Each side measured 2.5 centimeters.
What is the perimeter of Nadia’s square? Write an equation to model your work
10 cm; 4 x 2.5 = 10
400
Leticia and Jamal go to a bakery.
Jamal wants to buy 6 muffins. How much will this cost? Write an equation to model your work.
11.94; 6 x 1.99= 11.94
500
A credit card is 0.76 mm thick. How thick is a stack 103 credit cards?
760 mm; I moved the decimal point in 0.76 three places to the right.
500
Rounding to the nearest tenth, which of the following give an underestimate?
39.45 x 1.7
27.54 x 0.74
9.91 x 8.74
78.95 x 1.26
18.19 x 2.28
500
Alyssa paints 3 walls blue. Each of the walls is 8.3 feet tall and 7.5 feet wide.
Round the length and width to thenearest whole number. Then estimatethe area that Alyssa will paint. Write equations to model your work.
192 sq ft; 8 x 8= 64, 64 x 3= 192
500
One glass of lemonade has 115 calories. How many calories are in 3.5 glasses of lemonade? Write an equation to modelyour work.
115 x 3.5 = 402.5; 402.5 calories