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3.21×23= 3.21×2.3= 321×2.3=
32.1×0.23= 3.21×0.23= 321×0.023=
分析:先算出3.21×23=73.83,再根据积的变化规律;两数相乘,如果一个因数不变,另一个因数扩大或缩小几倍(0除外),积也会随之扩大或缩小相同的倍数,据此解答即可得到答案.
解答:
解:
3.21×23=73.83

3.21×2.3=7.383

321×2.3=738.3
32.1×0.23=7.383 3.21×0.23=0.7383 321×0.023=7.383
点评:此题主要考查的是积的变化规律的灵活应用.
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