题目内容
脱式计算.(能简算的要简算)
(1)
+
×
÷6
(2)24×(
+
)
(3)3-1÷(
+
×
)
(4)1.75×
+
×
+
(5)(
-
)÷(
+
)
(6)
+
+
+
+
+
.
(1)
3 |
8 |
3 |
4 |
2 |
3 |
(2)24×(
3 |
8 |
3 |
4 |
(3)3-1÷(
5 |
7 |
6 |
7 |
1 |
3 |
(4)1.75×
6 |
7 |
3 |
14 |
7 |
4 |
7 |
4 |
(5)(
5 |
8 |
1 |
4 |
8 |
9 |
1 |
3 |
(6)
1 |
42 |
1 |
56 |
1 |
72 |
1 |
90 |
1 |
110 |
1 |
132 |
分析:(1)先算乘法,再算除法,最后算加法;
(2)运用乘法分配律简算;
(3)先算小括号里面的乘法,再算小括号里面的加法,然后算括号外的除法,最后算括号外的减法;
(4)运用乘法分配律简算;
(5)同时运算两个小括号里面的减法和加法,最后算括号外的除法;
(6)
=
-
,
=
-
…;由此化简求解.
(2)运用乘法分配律简算;
(3)先算小括号里面的乘法,再算小括号里面的加法,然后算括号外的除法,最后算括号外的减法;
(4)运用乘法分配律简算;
(5)同时运算两个小括号里面的减法和加法,最后算括号外的除法;
(6)
1 |
42 |
1 |
6 |
1 |
7 |
1 |
56 |
1 |
7 |
1 |
8 |
解答:解:(1)
+
×
÷6,
=
+
÷6,
=
+
,
=
;
(2)24×(
+
),
=24×
+24×
,
=9+18,
=27;
(3)3-1÷(
+
×
),
=3-1÷(
+
),
=3-1÷1,
=3-1,
=2;
(4)1.75×
+
×
+
,
=
×
+
×
+
,
=
×(
+
+1),
=
×
,
=
;
(5)(
-
)÷(
+
),
=
÷
,
=
;
(6)
+
+
+
+
+
,
=(
-
)+(
-
)+(
-
)+(
-
)+(
-
)+(
-
),
=
-
+
-
+
-
+
-
+
-
+
-
,
=
-
,
=
.
3 |
8 |
3 |
4 |
2 |
3 |
=
3 |
8 |
1 |
2 |
=
3 |
8 |
1 |
12 |
=
11 |
24 |
(2)24×(
3 |
8 |
3 |
4 |
=24×
3 |
8 |
3 |
4 |
=9+18,
=27;
(3)3-1÷(
5 |
7 |
6 |
7 |
1 |
3 |
=3-1÷(
5 |
7 |
2 |
7 |
=3-1÷1,
=3-1,
=2;
(4)1.75×
6 |
7 |
3 |
14 |
7 |
4 |
7 |
4 |
=
7 |
4 |
6 |
7 |
3 |
14 |
7 |
4 |
7 |
4 |
=
7 |
4 |
6 |
7 |
3 |
14 |
=
7 |
4 |
29 |
14 |
=
29 |
8 |
(5)(
5 |
8 |
1 |
4 |
8 |
9 |
1 |
3 |
=
3 |
8 |
11 |
9 |
=
27 |
88 |
(6)
1 |
42 |
1 |
56 |
1 |
72 |
1 |
90 |
1 |
110 |
1 |
132 |
=(
1 |
6 |
1 |
7 |
1 |
7 |
1 |
8 |
1 |
8 |
1 |
9 |
1 |
9 |
1 |
10 |
1 |
10 |
1 |
11 |
1 |
11 |
1 |
12 |
=
1 |
6 |
1 |
7 |
1 |
7 |
1 |
8 |
1 |
8 |
1 |
9 |
1 |
9 |
1 |
10 |
1 |
10 |
1 |
11 |
1 |
11 |
1 |
12 |
=
1 |
6 |
1 |
12 |
=
1 |
12 |
点评:完成本题要注意分析式中数据,运用合适的简便方法计算.
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