Converting Metric Measurements

Date: 11/03/2005 at 00:32:16
From: Shayne
Subject: converting millimeters to centimeters

50 millimeters = ? centimeters; 3 meters = ? centimeters

I don't understand how to convert metric units.  Would I divide 50 by
10?  Would I multiply 3 times 10?

Date: 11/03/2005 at 07:22:11
From: Doctor Ian
Subject: Re: converting millimeters to centimeters

Hi Shayne,

Let's look at a similar question.  How would you convert from dollars
to dimes, or dimes to dollars?

If you have, say, 20 dollars, you know there are 10 dimes in each one,
so that's 

  20 dollars * 10 dimes per dollar = (20*10) dimes = 200 dimes

On the other hand, if you have 300 dimes, 

      300 dimes      300
  ---------------- = --- dollars = 30 dollars
   10 dimes/dollar    10

So you're multiplying or dividing by 10, depending on whether you need
more of a smaller unit, or less of a larger one.  

(You'd better have more dimes than dollars, right?  Or fewer dollars
than dimes.  So that tells you whether to multiply or divide.)

What does this have to do with centimeters and millimeters?  Well,
there are 10 millimeters in a centimeter, just as there are 10 dimes
in a dollar.  

Does this help?

- Doctor Ian, The Math Forum
  http://mathforum.org/dr.math/ 

Date: 11/04/2005 at 02:07:08
From: Shayne
Subject: Thank you (converting millimeters to centimeters)

Thank you so much, your explanation has made it easier for me to
understand centimeters and millimeters.  Thanks again for your help!