10.2*1.8= 如何简算
问题描述:
10.2*1.8= 如何简算
答
原式=(10+0.2)×1.8
=10×1.8+0.2×1.8
=18+0.36
=18.3654.9*0.38简算=(55-0.1)·0.38
=55·0.38-0.1·0.38
=20.9-0.038
=20.862