问题 解答题
计算下面各题,能简算的用简便方法计算.
820-20×24÷80=[135-(35+75)]×48=8×3×125=
55×45-45×45=24×19+24=
答案

(1)820-20×24÷80,

=820-480÷80,

=820-6,

=814;

(2)[135-(35+75)]×48,

=[135-35-75]×48,

=(100-75)×48,

=25×4×12,

=100×12,

=1200;

(3)8×3×125,

=8×125×3,

=1000×3,

=3000;

(4)55×45-45×45,

=(55-45)×45,

=10×45,

=450;

(5)24×19+24,

=24×(19+1),

=24×20,

=480.

单项选择题 B型题