Multiply and Divide Decimals by Power of Tens

Find the example of a question that is multiplying by a power of 10.

• 42 x 19

• 40 x 1.5

• 400 x 20

• 4.56 x 1,000

When you divide decimals by powers of ten,

• add as many zeroes as you see

• move the decimal to the left

• move the decimal to the right

• move the decimal wherever you want

Solve. 3.40 x 100

• 3.40

• 34.0

• 340

• 3,400

How do you know how many places to move the decimal when multiplying or dividing by a power of 10?

• Guess! You have a 50% chance of getting it right

• It doesn't matter. Math has many right answers.

• Count the number of zeros in the power of 10

• Ask your teacher.

Solve: 0.08 x 10,000

• .08

• 80

• 800

• 8,000

Solve: 50 x 3,000

• 15,000.0

• 150.00

• 1,500,000

• 150,000

Solve. 8.6 x 100

• 8.6

• 860

• 8,600

• .086

Solve. 5.42 divided by 10

• 54.2

• .542

• .0542

• 542

Divide 85 into 100 groups

• 8.5

• 85

• 850

• .85

• .085

3 divided by 10

• 3

• .3

• .03

• 30