四年级数题48×0.69+3.1×4.8用简便方法计算
根据两个因数相乘,一个因数扩大几倍,另一个因数同时缩小几倍,积不变。48×0.69+3.1×4.8 =4.8×6.9+3.1×4.8 =(6.9+3.1)×4.8 =10×4.8 =48
也可以这样算: 48*0.69+3.1*4.8 =48*0.69+0.31*48 =48*(0.69+0.31) =48*1 =48
48*(0.69+0.31) = 48
48*(0.69+0.31) = 48
48*(0.69+0.31) = 48
答:4.52*47+45.2*5.3 =45.2*4.7+45.2*5.3 =45.2*10 =452详情>>
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