题目内容
计算下面各题,能简算的要简算.
|
|
(
|
|
分析:(1)先算乘法,再算加法;
(2)先把除法变成乘法,再运用乘法分配律简算;
(3)先算小括号里面的加法,再算括号外的除法;
(4)先算小括号里面的除法,再算小括号里面的加法,最后算括号外的乘法.
(2)先把除法变成乘法,再运用乘法分配律简算;
(3)先算小括号里面的加法,再算括号外的除法;
(4)先算小括号里面的除法,再算小括号里面的加法,最后算括号外的乘法.
解答:解:(1)
+
×
,
=
+
,
=
;
(2)
÷9+
×
,
=
×
+
×
,
=(
+
)×
,
=1×
,
=
;
(3)(
+
)÷
,
=
×
,
=
;
(4)
×(
+
÷
),
=
×(
+
),
=
×1,
=
.
| 2 |
| 3 |
| 1 |
| 3 |
| 3 |
| 4 |
=
| 2 |
| 3 |
| 1 |
| 4 |
=
| 11 |
| 12 |
(2)
| 7 |
| 16 |
| 9 |
| 16 |
| 1 |
| 9 |
=
| 7 |
| 16 |
| 1 |
| 9 |
| 9 |
| 16 |
| 1 |
| 9 |
=(
| 7 |
| 16 |
| 9 |
| 16 |
| 1 |
| 9 |
=1×
| 1 |
| 9 |
=
| 1 |
| 9 |
(3)(
| 2 |
| 7 |
| 7 |
| 21 |
| 2 |
| 3 |
=
| 13 |
| 21 |
| 3 |
| 2 |
=
| 13 |
| 14 |
(4)
| 4 |
| 19 |
| 4 |
| 5 |
| 3 |
| 10 |
| 3 |
| 2 |
=
| 4 |
| 19 |
| 4 |
| 5 |
| 1 |
| 5 |
=
| 4 |
| 19 |
=
| 4 |
| 19 |
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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