题目内容
| 能简便计算的要简便计算. 6-
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分析:(1)根据连续减去两个数,等于减去这两个数的和简算;
(2)(4)运用加法交换律简算;
(3)先去括号,再运算加法交换律简算;
(5)运用加法交换律和结合律简算;
(6)运用加法交换律,以及连续减去两个数,等于减去这两个数的和简算.
(2)(4)运用加法交换律简算;
(3)先去括号,再运算加法交换律简算;
(5)运用加法交换律和结合律简算;
(6)运用加法交换律,以及连续减去两个数,等于减去这两个数的和简算.
解答:解:(1)6-
-
,
=6-(
+
),
=6-1,
=5;
(2)
-
+
,
=
+
-
,
=1-
,
=
;
(3)
-(
-
),
=
-
+
,
=
+
-
,
=1-
,
=
;
(4)
+
-
,
=
-
+
,
=1+
,
=1
;
(5)
+
+
+
,
=(
+
)+(
+
),
=1+1,
=2;
(6)
-
+
-
,
=(
+
)-(
+
),
=1-1,
=0.
| 3 |
| 11 |
| 8 |
| 11 |
=6-(
| 3 |
| 11 |
| 8 |
| 11 |
=6-1,
=5;
(2)
| 2 |
| 3 |
| 2 |
| 9 |
| 1 |
| 3 |
=
| 2 |
| 3 |
| 1 |
| 3 |
| 2 |
| 9 |
=1-
| 2 |
| 9 |
=
| 7 |
| 9 |
(3)
| 3 |
| 4 |
| 2 |
| 5 |
| 1 |
| 4 |
=
| 3 |
| 4 |
| 2 |
| 5 |
| 1 |
| 4 |
=
| 3 |
| 4 |
| 1 |
| 4 |
| 2 |
| 5 |
=1-
| 2 |
| 5 |
=
| 3 |
| 5 |
(4)
| 10 |
| 9 |
| 1 |
| 3 |
| 1 |
| 9 |
=
| 10 |
| 9 |
| 1 |
| 9 |
| 1 |
| 3 |
=1+
| 1 |
| 3 |
=1
| 1 |
| 3 |
(5)
| 7 |
| 16 |
| 9 |
| 20 |
| 9 |
| 16 |
| 11 |
| 20 |
=(
| 7 |
| 16 |
| 9 |
| 16 |
| 11 |
| 20 |
| 9 |
| 20 |
=1+1,
=2;
(6)
| 11 |
| 14 |
| 3 |
| 5 |
| 3 |
| 14 |
| 2 |
| 5 |
=(
| 11 |
| 14 |
| 3 |
| 14 |
| 2 |
| 5 |
| 3 |
| 5 |
=1-1,
=0.
点评:本题考查了分数加减法的简算,要注意分析数据,选择合适的简算方法运算.
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