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/
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