问题 解答题
脱式计算.
1-(
7
9
-
5
9

(87-62)×280

7.87+(5-3.245)
答案

(1)1-(

7
9
-
5
9
),

=1-

2
9

=

7
9

(2)(87-62)×280,

=25×280,

=25×4×70,

=100×70,

=7000;

(3)7.87+(5-3.245),

=7.87+1.755,

=9.625.

单项选择题
单项选择题