Question

1.3X2.7 0.56X27 31X0.27=的简便算法？

Answer 1

1.3 X 2.7
= (1 + 0.3) X (3 - 0.3)
= 1 X 3 - 1 X 0.3 + 0.3 X 3 - 0.3 X 0.3
= 3 - 0.3 + 0.9 - 0.09
= 3.51
这腔慧个方法不扒圆宏太推荐，春册因为将1.3与2.7都用乘法分配律展开较为复杂（有四项，并且变号容易出错）

因此，以下都只拆其中一个乘数：
1.3 X 2.7
= 1.3 X (3 - 0.3)
= 1.3 X 3 - 1.3 X 0.3
= 3.9 - 0.39
= 3.51

0.56 X 27
= (0.5 + 0.06) X 27
= 0.5 X 27 + 0.06 X 27
= 13.5 + 1.62
= 15.12

31 X 0.27
= 31 X (0.3 - 0.03)
= 31 X 0.3 - 31 X 0.03
= 9.3 - 0.93
= 8.37

仅供参考！

Answer 2

1.3×2.7
=1.3×3-1.3×0.3
=3.9-0.39
=3.51
0.56×27
=0.56×30-0.56×3
=16.8-1.68
=15.12
31×0.27
=31×0.3-31×0.03
=9.3-0.93
=8.37

Answer 3

1.3X2.7+0.56X27+31X0.27
=1.3X2.7+5.6X2.7+3.1X2.7
=（1.3+5.6+3.1）颂闷型野猜罩野X2.7
=10X2.7
=27