题目内容
计算下面各题,能简算的要简算
|
|
| ||||||||||||||||||
|
|
分析:(1)(3)按照从左到右的顺序计算;
(2)根据减法的性质简算,注意运算的结果是负数;
(4)运用乘法分配律简算;
(5)先算小括号里面的加法,再把除法变成乘法,运用乘法交换律简算.
(2)根据减法的性质简算,注意运算的结果是负数;
(4)运用乘法分配律简算;
(5)先算小括号里面的加法,再把除法变成乘法,运用乘法交换律简算.
解答:解:(1)
-
+
,
=
+
,
=
;
(2)
-(
+
),
=
-
-
,
=0-
,
=-
;
(3)
×
÷
,
=
÷
,
=
;
(4)
×
+
×
,
=(
+
)×
,
=1×
,
=
;
(5)
×(
+
)÷
,
=
×
×
,
=
×
×
,
=
×
,
=
.
| 5 |
| 6 |
| 4 |
| 5 |
| 3 |
| 10 |
=
| 1 |
| 30 |
| 3 |
| 10 |
=
| 1 |
| 3 |
(2)
| 4 |
| 5 |
| 4 |
| 5 |
| 1 |
| 4 |
=
| 4 |
| 5 |
| 4 |
| 5 |
| 1 |
| 4 |
=0-
| 1 |
| 4 |
=-
| 1 |
| 4 |
(3)
| 4 |
| 7 |
| 1 |
| 14 |
| 1 |
| 2 |
=
| 2 |
| 49 |
| 1 |
| 2 |
=
| 4 |
| 49 |
(4)
| 7 |
| 12 |
| 3 |
| 5 |
| 5 |
| 12 |
| 3 |
| 5 |
=(
| 7 |
| 12 |
| 5 |
| 12 |
| 3 |
| 5 |
=1×
| 3 |
| 5 |
=
| 3 |
| 5 |
(5)
| 5 |
| 9 |
| 2 |
| 9 |
| 1 |
| 6 |
| 5 |
| 12 |
=
| 5 |
| 9 |
| 7 |
| 18 |
| 12 |
| 5 |
=
| 5 |
| 9 |
| 12 |
| 5 |
| 7 |
| 18 |
=
| 4 |
| 3 |
| 7 |
| 18 |
=
| 14 |
| 27 |
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.
练习册系列答案
相关题目