Associated Topics || Dr. Math Home || Search Dr. Math

### Multiplying by a Power of Ten

```
Date: 10/31/2001 at 11:08:19
From: Mike
Subject: Give the power of ten (decimals)

Dear Dr. Math,

Can you help me with this problem? The directions are:

Give the power of ten that the decimal must be multiplied by to
eliminate the decimal point.

3.825   6.91    19.207

My mom and I can not seem to figure this out.
Thanks, Mike
```

```
Date: 10/31/2001 at 12:10:14
From: Doctor Peterson
Subject: Re: Give the power of ten (decimals)

Hi, Mike.

A power of ten is a number formed by multiplying a bunch of 10's
together, like 1000 = 10*10*10. (I use "*" as the multiplication
sign.)

When you multiply a number by ten, you move the decimal point one
place to the right; for instance

12.0 * 10 = 120.

1.2 * 10 = 12.

So if you have to move the decimal point three places to the right to
make a whole number, then you are multiplying by ten three times, and
this is the same as multiplying by 1000:

1.234 * 1000 = 1.234 * 10*10*10
= 12.34 * 10*10
= 123.4 * 10
= 1234.

In other words, just count the decimal places, write that many zeros
after a 1, and you have the number by which you have to multiply to
eliminate the decimal point:

1.234    1000
\_/     \_/
3       3

The number 1000 is written as the third power of 10, or

3
1000 = 10*10*10 = 10
\______/
3

Does that help?

- Doctor Peterson, The Math Forum
http://mathforum.org/dr.math/
```
Associated Topics:
Elementary Place Value
Elementary Square Roots
Middle School Exponents

Search the Dr. Math Library:

 Find items containing (put spaces between keywords):   Click only once for faster results: [ Choose "whole words" when searching for a word like age.] all keywords, in any order at least one, that exact phrase parts of words whole words

Submit your own question to Dr. Math
Math Forum Home || Math Library || Quick Reference || Math Forum Search