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用递等式计算.能简便计算的要简便计算.56×1221×715716×32+32×916(23+78-56)×243÷34-34÷3.

编辑:chaxungu时间:2026-04-27 14:17:37分类:小学数学题库

用递等式计算,能简便计算的要简便计算.
5
6
×
12
21
×
7
15

7
16
×32+32×
9
16

2
3
+
7
8
-
5
6
)×24
3
4
-
3
4
÷3.
(1)
5
6
×
12
21
×
7
15

=
5
6
×(
12
21
×
7
15
),
=
5
6
×
4
15

=
2
9


(2)
7
16
×32+32×
9
16

=(
7
16
+
9
16
)×32,
=1×32,
=32;

(3)(
2
3
+
7
8
-
5
6
)×24,
=
2
3
×24+
7
8
×24-
5
6
×24,
=16+21-20,
=37-20,
=17;

(4)3÷
3
4
-
3
4
÷3,
=4-
1
4

=3
3
4