Subject: What about decimals?

My sixth graders really took to this method.

We are starting dividing decimals by decimals. I am wondering how to approach this using this method: Problems like 8.268 divided by 3.5 Do you have some suggestions?

Thanks,
XXXX XXXXX

Hi XXXX,
 
I'm assuming that you saw these links about how to 
divide whole numbers and have decimals in the 
answer(quotient):
 
Decimal Examples
(4 places)
(16 places repeating)
 
But your question is about having decimals in the divisor 
and/or dividend.

How about this:
 
a. We can do problems like 28 / 2 = 14
 
b. We can do problems like 28 / 20 = 1.4 (see above)
 
c. The next step is problems like 28 / 200 = 0.14
   This is the same as above except that the first
   digit in the answer is 0.  I think it would make
   sense to have kids do a bunch of these before
   moving onto decimals in the divisor and/or dividend.
 
d. Once kids are good with a,b,c then maybe teach then
   that you can multiply BOTH the divisor and dividend
   by ten and it doesn't change the answer.  Same with
   dividing BOTH the divisor and dividend by ten.
   
   d.1 Maybe first start with dividing by ten to make
       the problem smaller;
       280/20 => 28/2
       2800/200 => 28/2
       28000/2000 => 28/2
 
   d.2 Then multiply by 10 to get rid of the decimals;
       28/0.2 => 280/2
       28/2.22 => 2800/222
       2.8/2 => 28/20
       8.268/3.5 => 8268/3500

Thanks for emailing me, and good luck
 
Jeff

Emailed to me in November 2008:
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