should be able to do simple addition and subtraction

来源: 4yrold 于 2008-07-17 07:15:48 [] [旧帖] [给我悄悄话] 阅读数 : (212 bytes)

quickly and accurately. Very important if you want your kids to excel in math in the future. Solid number concept, speed, and accuracy are the foundation for problem solving, multiplication, fraction and division

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