简便算法:1.25*2.5*8*12 3.8*99+3.8 2.78*7.8+2.78*3.2-2.78
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简便算法:1.25*2.5*8*12 3.8*99+3.8 2.78*7.8+2.78*3.2-2.78
![简便算法:1.25*2.5*8*12 3.8*99+3.8 2.78*7.8+2.78*3.2-2.78](/uploads/image/z/16635913-25-3.jpg?t=%E7%AE%80%E4%BE%BF%E7%AE%97%E6%B3%95%EF%BC%9A1.25%2A2.5%2A8%2A12+3.8%2A99%2B3.8+2.78%2A7.8%2B2.78%2A3.2-2.78)
1.25*2.5*8*12
= (1.25*8)*(2.5*4)*3
= 10*10*3
= 300
3.8*99+3.8
=3.8*(99+1)
=3.8*100
=380
2.78*7.8+2.78*3.2-2.78
=2.78*(7.8+3.2-1)
=2.78*10
=27.8
= (1.25*8)*(2.5*4)*3
= 10*10*3
= 300
3.8*99+3.8
=3.8*(99+1)
=3.8*100
=380
2.78*7.8+2.78*3.2-2.78
=2.78*(7.8+3.2-1)
=2.78*10
=27.8