题目内容
计算下面各题:(能简便计算的要简便计算)
(1)
÷(
+
)
(2)
×
+
×
(3)
÷
+
÷
(4)
-
÷
(5)(
+
)÷
(6)
÷(
+
)
(1)
| 14 |
| 25 |
| 1 |
| 5 |
| 1 |
| 2 |
(2)
| 7 |
| 13 |
| 8 |
| 9 |
| 8 |
| 9 |
| 6 |
| 13 |
(3)
| 1 |
| 4 |
| 5 |
| 8 |
| 3 |
| 4 |
| 5 |
| 8 |
(4)
| 4 |
| 5 |
| 4 |
| 15 |
| 2 |
| 5 |
(5)(
| 3 |
| 8 |
| 3 |
| 16 |
| 3 |
| 8 |
(6)
| 5 |
| 42 |
| 5 |
| 8 |
| 5 |
| 6 |
分析:(1)先算小括号里面的加法,再算括号外的除法;
(2)运用乘法分配律简算;
(3)先把除法变成乘法,再运用乘法分配律简算;
(4)先算除法,再算减法;
(5)先把除法变成乘法,再运用乘法分配律简算;
(6)先算小括号里面的加法,再算括号外的除法.
(2)运用乘法分配律简算;
(3)先把除法变成乘法,再运用乘法分配律简算;
(4)先算除法,再算减法;
(5)先把除法变成乘法,再运用乘法分配律简算;
(6)先算小括号里面的加法,再算括号外的除法.
解答:解:(1)
÷(
+
),
=
÷
,
=
;
(2)
×
+
×
,
=(
+
)×
,
=1×
,
=
;
(3)
÷
+
÷
,
=
×
+
×
,
=(
+
)×
,
=1×
,
=
;
(4)
-
÷
,
=
-
,
=
;
(5)(
+
)÷
,
=(
+
)×
,
=
×
+
×
,
=1+
,
=1
;
(6)
÷(
+
),
=
×
,
=
.
| 14 |
| 25 |
| 1 |
| 5 |
| 1 |
| 2 |
=
| 14 |
| 25 |
| 7 |
| 10 |
=
| 4 |
| 5 |
(2)
| 7 |
| 13 |
| 8 |
| 9 |
| 8 |
| 9 |
| 6 |
| 13 |
=(
| 7 |
| 13 |
| 6 |
| 13 |
| 8 |
| 9 |
=1×
| 8 |
| 9 |
=
| 8 |
| 9 |
(3)
| 1 |
| 4 |
| 5 |
| 8 |
| 3 |
| 4 |
| 5 |
| 8 |
=
| 1 |
| 4 |
| 8 |
| 5 |
| 3 |
| 4 |
| 8 |
| 5 |
=(
| 1 |
| 4 |
| 3 |
| 4 |
| 8 |
| 5 |
=1×
| 8 |
| 5 |
=
| 8 |
| 5 |
(4)
| 4 |
| 5 |
| 4 |
| 15 |
| 2 |
| 5 |
=
| 4 |
| 5 |
| 2 |
| 3 |
=
| 2 |
| 15 |
(5)(
| 3 |
| 8 |
| 3 |
| 16 |
| 3 |
| 8 |
=(
| 3 |
| 8 |
| 3 |
| 16 |
| 8 |
| 3 |
=
| 3 |
| 8 |
| 8 |
| 3 |
| 3 |
| 16 |
| 8 |
| 3 |
=1+
| 1 |
| 2 |
=1
| 1 |
| 2 |
(6)
| 5 |
| 42 |
| 5 |
| 8 |
| 5 |
| 6 |
=
| 5 |
| 42 |
| 24 |
| 35 |
=
| 4 |
| 49 |
点评:本题考查了四则混合运算,注意运算顺序和运算法则,灵活运用所学的运算定律进行简便计算.
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