资料简介
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www.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.com从上面的算式中,你发现了什么?这叫做乘法结合律。三个数相乘,先乘前两个数或者先乘后两个数,积不变。探索新知二
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www.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.comwww.youyi100.com根据乘法运算定律填上合适的数。12×32=32×,108×75=×.30×6×7=30×(6×),125×(8×40)=(×)×.12751087125840课堂检测三教材做一做
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