问题 解答题
计算下面各题(能简算的要简算)
①19.76-4
3
7
-3
4
7

②8
7
10
-8
11
20
+2
11
12

③2.5×1.25×32.
答案

①19.76-4

3
7
-3
4
7

=19.76-(4

3
7
+3
4
7
),

=19.76-8,

=11.76;

②8

7
10
-8
11
20
+2
11
12

=8+

7
10
-(8+
11
20
)+(2+
11
12
),

=8+

7
10
-8-
11
20
+2+
11
12

=(8-8+2)+(

7
10
-
11
20
+
11
12
),

=2+1

1
15

=3

1
15

③2.5×1.25×32,

=2.5×1.25×4×8,

=(2.5×4)×(1.25×8),

=10×10,

=100.

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单项选择题