问题 解答题
计算(能简算的要简算)
(1)
1
7
×(
19
27
×7)
(2)72×
5
9
-
1
4

(3)4-
5
12
×
4
12

(4)
1
3
×
5
6
+
1
3
×
1
2
答案

(1)

1
7
×(
19
27
×7),

=(

1
7
×7)×
19
27

=

19
27

(2)72×

5
9
-
1
4

=40-

1
4

=39

3
4

(3)4-

5
12
×
4
12

=4-

5
36

=3

31
36

(4)

1
3
×
5
6
+
1
3
×
1
2

=

1
3
×(
5
6
+
1
2
),

=

1
3
×
4
3

=

4
9

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单项选择题