7.89*10.1 (25+0.125)*0.8 0.25*38.6*4 3.2*10.2数学题用简便计算

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7.89*10.1 (25+0.125)*0.8 0.25*38.6*4 3.2*10.2数学题用简便计算
7.89*10.1 (25+0.125)*0.8 0.25*38.6*4 3.2*10.2
数学题用简便计算

7.89*10.1 (25+0.125)*0.8 0.25*38.6*4 3.2*10.2数学题用简便计算
7.89*10.1
=7.89*(10+0.1)
=78.9+0.789
=79.689
(25+0.125)*0.8
=25*0.8+0.125*0.8
=20+0.1
=20.1
0.25*38.6*4
=(0.25*4)*38.6
=1*38.6
=38.6
3.2*10.2
=3.2×(10+0.2)
=32+0.64
=32.64

难得啊