Quote:
Originally Posted by upstatedoc
Wtf Is this ass backwards witchcraft they are teaching the kids in school?
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There are tally marks for each of the digits. Add up the tally marks digit-by-digit and you've got your sum. Not how I learned it, but it's how I do addition in my head. Before you can do it in your head, you have to practice it on paper.
Hopefully they also get to learn some proofs. They're really valuable mental exercises.