If you don't teach children (or help them figure out how) to adroitlydo subtractions with minuends from 11 through 18, you will essentiallyforce them into options (1) or (2) above or something similar. Whereasif you do teach subtractions from 11 through 18, you give them the optionof using any or all three methods. Plus, if you are going to want childrento be able to see 53 as some other combination of groups besides 5 ten'sand 3 one's, although 4 ten's plus 1 ten plus 3 one's will serve, 4 ten'sand 13 one's seems a spontaneous or psychologically ready consequence ofthat, and it would be unnecessarily limiting children not to make it easyfor them to see this combination as useful in subtraction. ()


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