简算:32.4-12.4*1.8

问题描述:

简算:32.4-12.4*1.8

1.8*(18-12.4)=1.8*5.6=10.08

32.4-12.4*1.8=1.8*18-12.4*1.8=1.8*(18-12.4)

既然是简便方法,楼上两位从32.4看出是18*1.8,有点难了点
32.4-12.4*1.8=32.4-12.4*(2-0.2)=32.4-12.4*2+12.4*0.2
=32.4-24.8+2.48
=(32.4+2.48)-24.8
=34.88-24.8=10.08

=18*1.8 - 12.4*1.8
=1.8*(18-12.4)
=1.8*(5.6)
=(2-0.2)*(5.6)
=11.2-1.12
=10.08