12.5x0.25x0.8x40 =12.5x0.8x40x0.25 =1.25x8x40x1/4 =10x10 =100
有简便运算,简便运算就是先算能凑整的,那么看到25就想到4,看到125就想到8,因为乘积是100的倍数.(12.5*0.8)*(0.25*40)=10*10=100请采纳谢谢
12.5*400.8 =12.5*40+12.5*0.8 =50+10 =60
(8+0.8)X12.5=8X12.5+0.8X12.5=100+10=110.
你好: (0.8+8)x12.5 =0.8*12.5+8*12.5 =10+100 =110
1x12.5-0.8x12.5=12.5-10=2.5
(10*0.8)*12.5=10*10=100.
简便计算
0.8*72.4*12.5 =0.8*12.5*72.4 =10*72.4 =724 别忘采纳哦
40*0.8*0.25*12.5=(40*0.25)*(0.8*12.5)=10*10=100