Question

Multiplying and Dividing by Powers of 10 When multiplying a number by 10, move the decimal to the right. When multiplying a number by 0.1, move the decimal to the left. Why?

Answer 1

Sample Response: You move the decimal to the right when multiplying a number by 10 because you are making the number bigger. You move the decimal to the left when multiplying a number by 0.1 because you are making the number smaller.

Explanation:

hope this helps

Answer 2

Because we actually divide by 10 when a number is multiplied by 0.1.

Explanation:

Let
`a` be a number.

When we multiply a number by 10:

`a * 10 = 10 a` (One '0' is increased in the number)

For example:

`23 * 10 = 230`

Considering a decimal number:

`2.3 * 10 = 23`

Multiplying a number with 0.1 (which is actually
`(1)/(10)`) means dividing the number by 10.

`23* 0.1 =23* (1)/(10)=2.3`

Considering a decimal number:

`2.3 * 0.1 = 2.3 * (1)/(10) = 0.23`

Therefore, When multiplying a number by 0.1, move the decimal to the left.