题目内容
计算(能简算的要简算)
-
+
-
+(
-
)
-(
+
)
+
+
+
+
.
| 14 |
| 9 |
| 3 |
| 7 |
| 4 |
| 9 |
| 4 |
| 7 |
| 7 |
| 8 |
| 3 |
| 4 |
| 1 |
| 6 |
| 8 |
| 9 |
| 2 |
| 9 |
| 4 |
| 7 |
| 1 |
| 2 |
| 1 |
| 4 |
| 1 |
| 8 |
| 1 |
| 16 |
| 1 |
| 32 |
分析:(1)运用加法结合律,以及减法性质解答,
(2)先算括号里面的减法,再算加法解答,
(3)运用加法性质去掉括号,再按照从左到右顺序解答,
(4)化
=
-
,
=
-
,
=
-
,
=
-
解答.
(2)先算括号里面的减法,再算加法解答,
(3)运用加法性质去掉括号,再按照从左到右顺序解答,
(4)化
| 1 |
| 4 |
| 1 |
| 2 |
| 1 |
| 4 |
| 1 |
| 8 |
| 1 |
| 4 |
| 1 |
| 8 |
| 1 |
| 16 |
| 1 |
| 8 |
| 1 |
| 16 |
| 1 |
| 32 |
| 1 |
| 16 |
| 1 |
| 32 |
解答:解:(1)
-
+
-
,
=(
+
)-(
+
),
=2-1,
=1;
(2)
+(
-
),
=
+
,
=1
;
(3)
-(
+
),
=
-
-
,
=
-
,
=
;
(4)
+
+
+
+
,
=
+
-
+
-
+
-
+
-
,
=1-
,
=
.
| 14 |
| 9 |
| 3 |
| 7 |
| 4 |
| 9 |
| 4 |
| 7 |
=(
| 14 |
| 9 |
| 4 |
| 9 |
| 3 |
| 7 |
| 4 |
| 7 |
=2-1,
=1;
(2)
| 7 |
| 8 |
| 3 |
| 4 |
| 1 |
| 6 |
=
| 7 |
| 8 |
| 7 |
| 12 |
=1
| 11 |
| 24 |
(3)
| 8 |
| 9 |
| 2 |
| 9 |
| 4 |
| 7 |
=
| 8 |
| 9 |
| 2 |
| 9 |
| 4 |
| 7 |
=
| 2 |
| 3 |
| 4 |
| 7 |
=
| 2 |
| 21 |
(4)
| 1 |
| 2 |
| 1 |
| 4 |
| 1 |
| 8 |
| 1 |
| 16 |
| 1 |
| 32 |
=
| 1 |
| 2 |
| 1 |
| 2 |
| 1 |
| 4 |
| 1 |
| 4 |
| 1 |
| 8 |
| 1 |
| 8 |
| 1 |
| 16 |
| 1 |
| 16 |
| 1 |
| 32 |
=1-
| 1 |
| 32 |
=
| 31 |
| 32 |
点评:在解答能简算的要简算的题目时,要注意观察算式中各数之间的关系,灵活的选择并运用正确的简便算法,没有简便算法的,就要按照四则运算计算方法解答.
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