Place Values
When multiplying decimals, what is the first step you take in the problem?
Remove decimals (or pretend they aren't there)
1.5 x 1.5
2.25
6.5 ÷ 0.5
13
6.5 ÷ 0.5 = 65 ÷ 5 = 13
0.25 x 8
2
Anna bought 0.5 kg of apples for 2 dollars per kg. How much did she spend?
$1.00
0.5 x 2 = 1
Select all expressions that equal 5:
A) 8.0 ÷ 1.6
B) 5.4 ÷ 0.9
C) 7.5 ÷ 1.5
D) 11 ÷ 0.2
A, C, D
B (5.4 ÷ 0.9) = 6
2.6 x 0.3
0.78
26 x 3 = 78.0 *
*Shift your decimal two place values to the left*
0.75 ÷ 0.3
2.5
0.75 ÷ 0.3 = 75 ÷ 30 = 2.5
1.6 ÷ 4
0.4
A bottle holds 1.5 gallons of water. If you fill 5 bottles, how much water do you need?
7.5 gallons of water!
1.5 x 5 = 7.5
When dividing a decimal by a whole number, the first step you should take is to move the _________ to the ____ of the problem
When dividing a decimal by a whole number, the first step you should take is to move the decimal to the top of the problem.
8.1 x 0.7 =
5.67
81 x 7 = 567 *
Shift decimals two place values to the left
1 ÷ 0.125
1 ÷ 0.125 = 1000 ÷ 125 = 8
16.8 ÷ 2
8.4
Tom has 12.4 feet of ribbon. He cuts it into 4 equal pieces. How long is each piece?
3.1 feet per piece!
When dividing a whole number by a decimal, you can convert the decimal to a fraction, then use this strategy to get the product
Keep, Change, Flip
4 ÷ 0.25 = 4 x 4/1 = 16/1 or 16
0.117 x 0.3
0.0351
117 x 3 = 351
Shift decimal four place values to the left
19.2 ÷ 0.48
40
5.7 x 3
17.1
A car travels 0.6 miles per mile. How far will it travel in 60 minutes?
36 miles
In order to multiply a number by 1000, you need to shift your place values ________ places to the _______ of the decimal.
In order to multiply a number by 1000, you need to shift your place values 3 places to the right.
Example:
2.5 x 10 = 25
2.5 x 100 = 250
2.5 x 1000 = 2500
0.125 x 0.25 =
0.03125
125 x 25 = 3125
Shift your decimal five place values to the left
123.4 ÷ 5
123.4 ÷ 5 = 1234 ÷ 50 = 24.68
9.8 x 7
68.6
Sarah ran 56.7 miles over the past week. She wants to divide this distance into 7 equal parts, to see how many miles she ran per day. How far is each part?
8.1 miles