Multiplying by Powers of 10
5.6 x 104 = ?
56,000
4/10
40/100
400/1000
6 x 0.07 = ?
0.42
If a rectangle had an length of 5.6 feet and a width of 4.3 feet, what is the perimeter of the rectangle?
19.3 feet
Fill in the blank: 102 x ____ = 62
0.62 or .62
0.34 x 103 = ?
340
Write a fraction expression that's equal to 0.07 x 0.9
Sample Answers:
7/100 x 9/10
7/100 x 90/100
114 x 5.5 = ?
627
If a rectangle had an length of 5.6 feet and a width of 4.3 feet, what is the area of the rectangle?
24.08 square feet
6.32 x 0.15 = ?
0.948
Natalie wants to mail Thanksgiving cards to all of her family. A stamp for each card costs $0.51. Natalie wants to mail 10 cards. What is the total cost of mailing her 10 cards? Explain how you know?
$5.10
I know this because multiplying by is 10 is like multiplying by 101 which means the decimal point moves one place to the right.
Write a fraction expression that's equal to 0.8 x 0.54
Sample Answers:
80/100 x 54/100
8/10 x 54/100
3.72 x 0.43 = ?
1.5996
Ms. Marion drew a square on the board. Each side measured 4.3 inches. What is the perimeter of Ms. Marion's square? Write an equation to model your work.
4.3 x 4 = 17.2 inches
4.3+4.3+4.3+4.3= 17.2
Morgan needs 0.34 feet of wrapping paper for each present she's wrapping. She's wrapping 23 presents! How much wrapping paper does she need for all of her presents? Write an equation with the answer.
0.34 x 23 = 7.82 feet of wrapping paper
Write the answer for each expression:
1. 4.06 x 102
2. 0.406 x 101
3. 4.06 x 10
4. 0.406 x 104
1. 406
2. 4.06
3. 40.6
4. 4,060
What expressions equal 0.98 x 0.3? Write all the correct responses.
A. 98/10 x 3/100 B. 98/100 x 30/100
C. 98/100 x 3/10 D. 98/1 x 3/100
B. 98/100 x 30/100
C. 98/100 x 3/10
7.95 x 2.48 = ?
19.716
Mrs. Lambert wants to plant her 4 gardens. Each garden is 8.7 feet long by 4.2 feet wide.
Round the length and width to the nearest WHOLE NUMBER. Then estimate the area that Mrs. Lambert needs to plant. Write equations to model your work.
9 x 4 = 36 square feet for one garden
36 x 4 = 144 square feet
Andrew wants to buy 15 balloons. Each balloon costs $0.89. He uses partial products to find his total. He says, "$25.50 is much more than my estimate of 15 x $1 = $15, so my estimate is too low." Do you agree? Explain.
Andrew's work:
10 x 0.9 = 9
10 x 0.8 = 8
5 x 0.9 = 4.5
5 x 0.8 = 4
9+8+4.50+4= $25.50
No; $15 was an overestimate because he rounded $0.89 to $1. So, the actual amount must be less than $15. His partial products are not correct. The actual total is $13.35.
A Spotted Lantern Fly egg mass has an area that measures 1.5 square inches. What is the area of 103 egg masses?
1,500 square inches
What expressions equal 0.87 x 0.6? Write all the correct responses.
A. 87/100 x 6/100 B. 87/100 x 60/100
C. 87/100 x 6/10
B. 87/100 x 60/100
C. 87/100 x 6/10
Charlie runs 3.45 miles each day. How many total miles will he run after 10 days? Explain how you got your answer.
34.5 miles
I moved the decimal point in 3.45 one place to the right.
Mrs. Lambert wants to plant her 4 gardens. Each garden is 8.7 feet long by 4.2 feet wide.
Find the exact area of the gardens. Write your equations to model your work.
8.7 x 4.2 = 36.54 square feet for one garden
36.54 x 4 = 146.16 square feet for 4 gardens
Olivia plays basketball for a total of 2.6 hours on Saturdays. On Sundays, she plays basketball for 3.5 hours. How many hours in total does Olivia play basketball in a year? Reminder: There are 52 weeks in a year
2.6 + 3.5 = 6.1 hours each week
6.1 x 52 = 317.2 hours a year