Question

98.6x98.6–98.5x98.7简便计算？

Answer 1

98.6x98.6–98.5x98.7简便计算：

98.6x98.6–98.5x98.7

=98.6x98.6–(98.6-0.1)x(98.6+0.1)

=98.6x98.6–98.6x98.6+0.1x0.1

=0.01

扩展资料

简便计算方法：

去尾法。

在减法计算时，若减数和被减数的尾数相同，先用被减数减去尾数相同的减数，能使计算简便。

例题

2356-159-256

=2356-256-159

=2100-159

=1941

算式中第二个减数256与被减数2356的尾数相同，可以交换两个数的位置，让2356先减256，可使计算简便。

Answer 2

98.6x98.6–98.5x98.7
=98.6x98.6–(98.6-0.1)x(98.6+0.1)
=98.6x98.6–98.6x98.6+0.1x0.1
=0.01

Answer 3

98.6×98.6-（98.6-0.1）×（98.6+0.1）＝98.6×98.6-（98.6×98.6-0.1×0.1）
＝98.6×98.6-98.6×98.6＋0.1×0.1
＝0.01