Question

18.9-4.6x2.4简便计算？

Answer 1

变形为前同后补简便计算。
18.9-4.6×2.4
=18.9-(2+2.6)×2.4
=18.9-(2×2.4+2.6×2.4)
=18.9-(4.8+6.24)
=18.9-11.04
=7.86

Answer 2

这个就是脱式计算，没啥简便。
18.9－4.6×2.4
＝18.9－11.04
＝7.86

Answer 3

18.9－4.6×2.4
＝18.9－4.6×2－4.6×0.4
＝18.9一9.2一1.84
＝9.7一1.8一0.o4
＝7.9一0.04
＝7.86

Answer 4

18.9-4.6x2.4
= 18.9－（5-0.4）×2.4

=18.9－5×2.4+0.4×2.4

=18.9-12+0.96

=6.9+0.96

=7.86

Answer 5

这个算式简便的算法，四点6×2点四可以把2.4变成3-0点六，这样算乘法的时候相对是比较简单的口算，可以直接得出。