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I found this several years ago
By Risa
This is something I got from a website forum several years ago. Since it involves making sure all the columns align correctly, it's on a Word document, rather than just copying and posting it here, I'm pasting just up to the division example. If this is something that interests you, you can download the document for the rest of the information.
double digit division
Posted by Sandy on 2/19/04
This is a tip for where to start in the estimating:
Example:
966 รท 42
Have them look at the digit in the ones place of the divisor
42
If this number is 0-4 (in this case it is) they estimate by the digit in the tens place in the divisor, 4.
So, they will say to themselves:
How many 4's are in 9. The answer is "2" (This is their "estimate") so they multiply 42 times 2 and get 84 .
After they subtract they have 126 ---
Again, they ask how many 4's are in 12 ---- the answer is 3 ----
They multiply 42 times 3 and get 126. This is just an example.
The other rule is that if the number in the ones place of the divisor is MORE than 4, they will estimate using one number HIGHER than the number in the tens place of the divisor.
(There's more... In the attached document, this continues with an actual division problem and further explanation.)
Double Digit Division
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