题目内容
| 计算 能简算则简算 | 1- | |
解:(1)
+
+
,
=(
)
,
=1+
,
=1
;
(2)1-
-
,
=1-(
+
),
=1-1,
=0;
(3)
+
+
,
=
+
,
=
,
=
;
(4)
-(
-
),
=
-
+
,
=(
)-
,
=1-
,
=
;
(5)
+
+
,
=1+
,
=1
;
(6)
-
+
-
,
=
+
-
-
,
=(
+
)-(
+
),
=
,
=
.
分析:(1)运用加法交换律简算;
(2)根据连续减去两个数等于减去这两个数的和来简算;
(3)先通分,再按照从左到右的顺序计算;
(4)先去掉括号,再根据加法交换律简算;
(5)按照从左到右的顺序计算;
(6)先运用加法交换律交换加数的位置,再根据连续减去两个数等于减去这两个数的和来简算.
点评:本题考查了加减法的简便运算,要记住这些方法,并能灵活运用.
=(
=1+
=1
(2)1-
=1-(
=1-1,
=0;
(3)
=
=
=
(4)
=
=(
=1-
=
(5)
=1+
=1
(6)
=
=(
=
=
分析:(1)运用加法交换律简算;
(2)根据连续减去两个数等于减去这两个数的和来简算;
(3)先通分,再按照从左到右的顺序计算;
(4)先去掉括号,再根据加法交换律简算;
(5)按照从左到右的顺序计算;
(6)先运用加法交换律交换加数的位置,再根据连续减去两个数等于减去这两个数的和来简算.
点评:本题考查了加减法的简便运算,要记住这些方法,并能灵活运用.
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