Multiplying Decimals by Powers of 10
0.12 x 101
1.2
112 x 8.9
996.8
1.3 x 2.9
3.77
Sarah bought 3.4 pounds of apples at $1.95 per pound. How much did Sarah spend on apples?
$6.63
Write two expressions as a fraction that are equivalent to 0.09 x 0.4
Sample answers:
9/100 x 4/10
90/1000 x 40/100
9/100 x 400/1000
0.043 x 102
4.3
45.5 x 2
91
7.3 x 9.3
67.89
A plastic card is .88 mm thick. How thick is a stack of 103 cards? Explain.
880 mm thick. I moved the decimal point 3 places to the right, and added a zero on the end.
Look at the decimal grid on the board to answer the following question:
Pauline shaded the decimal grid on the board as shown: Write an expression that shows the area that she colored. Then evaluate the expression.
0.4 x 0.5 = 0.20
0.98 x 104
9,800
756 x 0.7
529.2
0.05 x 0.9
0.045
Joe will have rode 123.4 miles. You move the decimal point to the right one time.
Ryan drew a square in his notebook. Each side measured 1.8 cm.
What is the perimeter of the square? Write an equation to model your work
1.8 x 4 = 7.2 cm is the perimeter
0.321 x 102
32.1
7.89 x 25
197.25
1.2 x 9.45
11.34
Amanda painted each of her 2 walls green. Each of the walls measured 7.2 ft x 9.9 ft.
Round the length and width to the nearest whole number. Then estimate the area that Amanda will paint. Remember that there are 2 walls.
7 x 10 = 70 square feet
70 x 2 = 140 square feet total
Amanda painted each of her 2 walls green. Each of the walls measured 7.2 ft x 9.9 ft.
Find the exact area that Amanda will have to paint her walls. Please write equations to model your work. Remember that there are two walls.
7.2 x 9.9 = 71.28 square feet
71.28 x 2 = 142.56 square feet
When multiplying a decimal by a power of 10, you know your answer is correct because the product is always _________________ the original decimal in the problem.
136 x 0.98
133.28
96.3 x 0.33
31.779
One glass of sweetened iced tea is 165 calories. How many calories are in 4.5 classes? Write an equation and solve.
742.5 calories are in 4.5 glasses
Ryan drew a square in his notebook. Each side measured 1.8 cm.
What is the area of the square? Write an equation to model your work.
1.8 x 1.8 = 3.24 square cm is the area.