问题 解答题

用简便方法计算.

4.05-2.8-0.2 3.25÷2.5÷4 5.63×49+4.37×49.

答案

(1)4.05-2.8-0.2,

=4.05-(2.8+0.2),

=4.05-3,

=1.05;

(2)3.25÷2.5÷4,

=3.25÷(2.5×4),

=3.25÷10,

=0.325;

(3)5.63×49+4.37×49,

=(5.63+4.37)×49,

=10×49,

=490.

单项选择题
单项选择题