问题 解答题
用简便算法计算,写出简算过程
7.8×1038.5×7.5+8.5×2.51.25×0.63×8.
答案

(1)7.8×103,

=7.8×(100+3),

=7.8×100+7.8×3,

=780+23.4,

=803.4;

(2)8.5×7.5+8.5×2.5,

=8.5×(7.5+2.5),

=8.5×10,

=85;

(3)1.25×0.63×8,

=(1.25×8)×0.63,

=10×0.63,

=6.3.

单项选择题
单项选择题