题目内容
脱式计算
|
|
|
|
分析:(1)按照从左到右的顺序计算;
(2)运用加法结合律简算;
(3)先算小括号里面的加法,再算括号外的减法;
(4)运用加法交换律和结合律简算.
(2)运用加法结合律简算;
(3)先算小括号里面的加法,再算括号外的减法;
(4)运用加法交换律和结合律简算.
解答:解:(1)
-
+
,
=
+
,
=
;
(2)
+
-
,
=
+(
-
),
=
+
,
=
;
(3)
-(
+
),
=
-
,
=
;
(4)
+
+
+
,
=(
+
)+(
+
),
=1+1,
=2.
| 5 |
| 12 |
| 3 |
| 8 |
| 2 |
| 3 |
=
| 1 |
| 24 |
| 2 |
| 3 |
=
| 17 |
| 24 |
(2)
| 3 |
| 4 |
| 11 |
| 18 |
| 1 |
| 9 |
=
| 3 |
| 4 |
| 11 |
| 18 |
| 1 |
| 9 |
=
| 3 |
| 4 |
| 1 |
| 2 |
=
| 5 |
| 4 |
(3)
| 7 |
| 8 |
| 2 |
| 5 |
| 1 |
| 10 |
=
| 7 |
| 8 |
| 1 |
| 2 |
=
| 3 |
| 8 |
(4)
| 10 |
| 11 |
| 5 |
| 7 |
| 1 |
| 11 |
| 2 |
| 7 |
=(
| 10 |
| 11 |
| 1 |
| 11 |
| 2 |
| 7 |
| 5 |
| 7 |
=1+1,
=2.
点评:本题考查了分数的加减混合运算,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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