Multiplying and Dividing Numbers by Powers of 10

​Multiplying and Dividing by Powers of 10

By John Santos

• Use knowledge of place value to multiply and divide whole numbers and decimals by any positive power of 10.

Multiplying and Dividing by Powers of 10

Learning Target

Let's review!

Place value

• Place value is the concept that the position of a digit in a number determines its value.

  📍 For example, in the number 345, the '3' is in the hundreds place, so its value is 300. The '4' is in the tens place, so its value is 40, and the '5' is in the ones place, with a value of 5.

PLACE VALUE CHART

Multiple Choice

What is the place value of the 4 in 471,902?

• 400,000

• 400

• hundreds

• hundred thousands

Multiple Choice

What is the value of the 5 in 25,089?

• hundreds

• 500

• thousands

• 5,000

Multiple Choice

What is the place value of the underlined digit?

0927.5512809

• thousandths

• hundredths

• 1000

• 0.001

Multiple Choice

Which of the following has 7 in thousandths place?

• 7541.123

• 5.457

• 6.1267

• 4542.765

Multiple Choice

What is the value of the 4 in  92.024 ?

• 4
• 0.004
• 40
• 0.04

Let's review!

Powers of 10

• Powers of 10 are a way of expressing numbers that are multiples of 10. They are written in the form of an exponential expression, where the base is 10 and the exponent is an integer. The exponent tells you how many times to multiply 10 by itself.

Multiple Choice

What is another way to write 10³

• 10
• 30
• 100
• 1,000

Multiple Choice

What is 10⁸?

• 10,000
• 100,000
• 100,000,000
• 1,000,000,000

Multiple Choice

10 x 10 x 10 x 10 can be written as 10 to what power?

• 10
• 10²
• 10³
• 10⁴

Multiple Choice

What is 10⁰?

• 0
• 1
• 10
• 100

Introductory Activity

• Form a group of 3.

• Think of a 4-digit number.

• Insert a decimal point anywhere in between two of your selected numbers or at either end.

• Multiply the number you formed by 10, 100, and 1000.

• Divide the number you formed by 10, 100, and 1000.

Open Ended

What strategy can be used in multiplying and d numbers by powers of 10?

Open Ended

How does a digit's value change when you multiply it by 10? by 100? by 1000?

Multiple Choice

Multiply 62.397 by 10

• 6239.7

• 623.97

• 62.40

• 62397.0

Multiple Choice

What is 10² x 892

• 892

• 8,920

• 89,200

• 892,000

Multiple Choice

0.0867 x 100

• 86.7
• 8.67
• 0.867

Multiple Choice

0.0891 x 10⁴

• 8.91
• 8,910
• 891
• 89.1

Multiple Choice

12.33÷10

• 1,233

• 0.1233

• 123.3

• 1.233

Multiple Choice

107 ÷ 10³

• 1.07
• .107
• 107,000
• 10.7

Multiple Choice

What is 19.7 ÷ 10⁴?

• 1.97
• 0.197
• 197
• 0.00197

Open your book to page 131 and answer Exercise 9A, 1, a-j