<< The basic procedure is this:
1)For each addend, add the digits together, divide by nine, and write down
the remainder. (Or, in slightly more high-level terms, find the value of
this sum MOD 9)
2)Add the remainders of the addends. Divide this sum by nine and write down
the remainder.
3)Do the same with the computed sum of the original problem
4)If the two match, then there is a very good, although not 100%, chance
that you did your addition problem correctly. >>
( FYI, Kathy was kind enough to send me this explaination of casting out
9's!!)
Kathy-
Thanks for the info! I think I'll just stick with using my TI-92 for all
addition problems! 8-) ;->
Karen
Orange Coast College
http://members.aol.com/coolmath2/coolmath.htm
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