Question

小数简便计算

1、（4乘0.4乘0.25）乘8乘7乘1.25 2、48乘1.25加50乘1.25乘0.2乘8
3、4.7乘2.8加3.6乘9.4
4、3.5÷1.4
5、55.5乘44.5加555乘5.65减55.5
弄错了第一题是这样的
1、（4加0.4乘0.25）乘8乘7乘1.25

Answer 1

（4乘0.4乘0.25）乘8乘7乘1.25 = 4*0.25*0.4*8*7*1.25

=1*0.4*8*7*1.25
=0.4*8*7*1.25
=0.4*7*2*4*1.25
=0.4*7*2*5
=0.4*2*5*7
=0.4*10*7
=4*7=28

48乘1.25加50乘1.25乘0.2乘8

=48*1.25+50*1.25*0.2*8
=1.25*(48+50*0.2*8)
=1.25*(48+10*8)
=1.25*(48+80)

=1.25*(100+4*7)
=125+1.25*4*7
=125+35
=160

4.7乘2.8加3.6乘9.4

4.7*2.8+3.6*9.4
=4.7*2.8+3.6*2*4.7
=4.7*(2.8+2*3.6)
=4.7*10
=47

3.5÷1.4
=0.7*5/2*0.7
=5/2
=2.5

55.5乘44.5加555乘5.65减55.5
=55.5*44.5+55.5*10*5.65-55.5
=55.5*(44.5+56.5-1)
=55.5*100
=5550

Answer 2

先算能算出来整数的

追问

我只是不会写