Question

0.65+19.1×6.5怎样用简便方法？

Answer 1

结果是124.8，逆向运用乘法分配律可以简便求得结果，具体计算过程见附图

Answer 2

0.65+19.1×6.5
=0.65+19.1×10×0.65
=0.65×(1+19.1×10)
=0.65×192
=124.8

Answer 3

0.65+19.1×6.5
=6.5×0.1+19.1×6.5
=6.5×(0.1+19.1)
=6.5×19.2
=6.5×20－6.5×0.8
=130－5.2
=124.8

Answer 4

0.65其实就等于6.5×0.1。也就是说0.65×1=6.5×0.1。6.5×0.1+19.1×6.5=6.5×括号里19.1+0.1过起来=6.5×19.2=124.8。运用的简便运算规律是乘法分配律。

Answer 5

因为0.65＝6.5×0.1，所以原式等于6.5×0.1+19.1×6.5，再利用乘法分配律得到6.5×（0.1+19.1）＝124.8