简便计算。

更新时间2019-09-15 08:44:16

第一个式子：=0.96*（3.84*10+61.6）=0.96*100=96

第二个式子：=0.029*（0.45*100+4.2*10+13）=0.029*100=2.9

=3.84×9.6+9.6×6.16

=9.6×（3.84+6.16）

=9.6×10

=96

 

=2.9×0.45+2.9×0.42+2.9×0.13

=2.9×（0.45+0.42+0.13）

=2.9×1

=2.9

注意小数点移动要保证两个乘数的小数位数之和是不变的

5.

3.84×9.6+0.96×61.6

=3.84×10×0.96+0.96×61.6

=38.4×0.96+0.96×61.6

=0.96×(38.4+61.6)

=0.96×100

=96

2.9×0.45+0.29×4.2+0.029×13

=2.9×0.45+0.29×10×0.42+(0.029×100)×(13÷100)

=2.9×0.45+2.9×0.42+2.9×0.13

=2.9×(0.45+0.42+0.13)

=2.9×1

=2.9