题目内容
简便计算
(1)
×
-
×
(2)(
+
-
)×48
(3)
×
+
÷9
(4)32×
.
(1)
9 |
5 |
2 |
3 |
4 |
5 |
2 |
3 |
(2)(
5 |
24 |
7 |
12 |
2 |
3 |
(3)
3 |
4 |
1 |
9 |
1 |
4 |
(4)32×
13 |
33 |
分析:(1)运用乘法分配律的逆运算简算;
(2)运用乘法分配律简算;
(3)把除法改为乘法,运用乘法分配律的逆运算简算;
(4)把32看做33-1,运用乘法分配律简算.
(2)运用乘法分配律简算;
(3)把除法改为乘法,运用乘法分配律的逆运算简算;
(4)把32看做33-1,运用乘法分配律简算.
解答:解:(1)
×
-
×
,
=(
-
)×
,
=1×
,
=
;
(2)(
+
-
)×48,
=
×48+
×48-
×48,
=10+28-32,
=6;
(3)
×
+
÷9,
=
×
+
×
,
=(
+
)×
,
=1×
,
=
;
(4)32×
,
=(33-1)×
,
=33×
-
,
=13-
,
=12
.
9 |
5 |
2 |
3 |
4 |
5 |
2 |
3 |
=(
9 |
5 |
4 |
5 |
2 |
3 |
=1×
2 |
3 |
=
2 |
3 |
(2)(
5 |
24 |
7 |
12 |
2 |
3 |
=
5 |
24 |
7 |
12 |
2 |
3 |
=10+28-32,
=6;
(3)
3 |
4 |
1 |
9 |
1 |
4 |
=
3 |
4 |
1 |
9 |
1 |
4 |
1 |
9 |
=(
3 |
4 |
1 |
4 |
1 |
9 |
=1×
1 |
9 |
=
1 |
9 |
(4)32×
13 |
33 |
=(33-1)×
13 |
33 |
=33×
13 |
33 |
13 |
33 |
=13-
13 |
33 |
=12
20 |
33 |
点评:此题主要考查学生对乘法分配律的掌握与运用情况.
练习册系列答案
相关题目