Question

用简便方法计算63O÷42x6 ，390÷52x4

Answer 1

解:①可以运用乘法交换律和结合律进行计算，先计算乘法再将630除以它们的积。计算过程
630÷42ⅹ6
=(630ⅹ6)÷42
=3780÷42
=90。
②可以运用乘法交换律和结合律进行计算。先计算乘法，然后将390除以它们的积。计算过程
390÷52ⅹ4
=(390ⅹ4)÷52
=1560÷52
=30。

Answer 2

回答：
630÷42×6
=630÷（6×7）÷6
=630÷6÷7×6
=630÷7
=90
390÷52×4
=390÷（4×13）×4
=390÷4÷13×4
=390÷13
=30
运用了拆分法

Answer 3

630÷42×6
=630÷7÷6×6
=630÷7
=90，
390÷52×4
=390÷13÷4×4
=390÷13
=30

Answer 4

630÷42×6=630×6/42=630×1/7=90
390÷52×4=390×4/52=390×1/13=30

Answer 5

630/42x6
=630x6/(7x6)
=630x6/7/6
=90
390/52x4
=390x4/(13x4)
=390x4/13/4
=30