题目内容
用你喜欢的方法算:
÷7+
×
-(
-
)
+
×
÷2
×(
+
)+
(
+
)×
+
.
5 |
12 |
7 |
12 |
1 |
7 |
7 |
8 |
5 |
9 |
1 |
8 |
1 |
6 |
3 |
4 |
2 |
3 |
12 |
5 |
5 |
6 |
3 |
4 |
4 |
5 |
(
24 |
19 |
16 |
17 |
1 |
8 |
15 |
17 |
分析:(1)除法转化成乘法后运用乘法分配律进行简算;
(2)去括号后运用加法结合律进行简算;
(3)按运算顺序和计算法则计算;
(4)运用乘法分配律进行简算;
(5)先运用乘法分配律计算,再运用加法结合律进行简算.
(2)去括号后运用加法结合律进行简算;
(3)按运算顺序和计算法则计算;
(4)运用乘法分配律进行简算;
(5)先运用乘法分配律计算,再运用加法结合律进行简算.
解答:解:(1)
÷7+
×
,
=
×
+
×
,
=(
+
)×
,
=1×
,
=
;
(2)
-(
-
),
=
-
+
,
=
+
-
,
=1-
,
=
;
(3)
+
×
÷2,
=
+
×
×
,
=
+
,
=
+
,
=
;
(4)
×(
+
)+
=
×
+
×
+
,
=2+
+
,
=3
+
,
=4
;
(5)(
+
)×
+
,
=
×
+
×
+
,
=
+
+
,
=
+(
+
),
=
+1,
=1
.
5 |
12 |
7 |
12 |
1 |
7 |
=
5 |
12 |
1 |
7 |
7 |
12 |
1 |
7 |
=(
5 |
12 |
7 |
12 |
1 |
7 |
=1×
1 |
7 |
=
1 |
7 |
(2)
7 |
8 |
5 |
9 |
1 |
8 |
=
7 |
8 |
5 |
9 |
1 |
8 |
=
7 |
8 |
1 |
8 |
5 |
9 |
=1-
5 |
9 |
=
4 |
9 |
(3)
1 |
6 |
3 |
4 |
2 |
3 |
=
1 |
6 |
3 |
4 |
2 |
3 |
1 |
2 |
=
1 |
6 |
1 |
4 |
=
2 |
12 |
3 |
12 |
=
5 |
12 |
(4)
12 |
5 |
5 |
6 |
3 |
4 |
4 |
5 |
=
12 |
5 |
5 |
6 |
12 |
5 |
3 |
4 |
4 |
5 |
=2+
9 |
5 |
4 |
5 |
=3
4 |
5 |
4 |
5 |
=4
3 |
5 |
(5)(
24 |
19 |
16 |
17 |
1 |
8 |
15 |
17 |
=
24 |
19 |
1 |
8 |
16 |
17 |
1 |
8 |
15 |
17 |
=
3 |
19 |
2 |
17 |
15 |
17 |
=
3 |
19 |
2 |
17 |
15 |
17 |
=
3 |
19 |
=1
3 |
19 |
点评:此题考查学生的计算能力,细心计算,并注意恰当运用定律进行简算.
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