题目内容
怎样简便就怎样算:
+(
-
)×
;
÷
+0.75×8;
11-
-2.125;
12×(
+
-
).
| 2 |
| 3 |
| 4 |
| 5 |
| 2 |
| 3 |
| 5 |
| 3 |
| 3 |
| 4 |
| 1 |
| 6 |
11-
| 7 |
| 8 |
12×(
| 1 |
| 4 |
| 1 |
| 6 |
| 1 |
| 3 |
分析:
+(
-
)×
先根据乘法分配律展开,然后再进一步计算即可;
÷
+0.75×8把0.75化成
,再根据乘法分配律进行计算即可;
11-
-2.125把
化成0.875,分别减去这两个数,就是减去这两个数的和,再进一步计算即可;
12×(
+
-
)根据乘法分配律进行计算即可.
| 2 |
| 3 |
| 4 |
| 5 |
| 2 |
| 3 |
| 5 |
| 3 |
| 3 |
| 4 |
| 1 |
| 6 |
| 3 |
| 4 |
11-
| 7 |
| 8 |
| 7 |
| 8 |
12×(
| 1 |
| 4 |
| 1 |
| 6 |
| 1 |
| 3 |
解答:解:算:
+(
-
)×
=
+
×
-
×
=
+
-
=2-
=
;
÷
+0.75×8
=
×6+
×8
=
×(6+8)
=
×14
=
;
11-
-2.125
=11-0.875-2.125
=11-(0.875+1.125)
=11-2
=9;
12×(
+
-
)
=12×
+12×
-12×
=3+2-4
=1.
| 2 |
| 3 |
| 4 |
| 5 |
| 2 |
| 3 |
| 5 |
| 3 |
=
| 2 |
| 3 |
| 4 |
| 5 |
| 5 |
| 3 |
| 2 |
| 3 |
| 5 |
| 3 |
=
| 2 |
| 3 |
| 4 |
| 3 |
| 10 |
| 9 |
=2-
| 10 |
| 9 |
=
| 8 |
| 9 |
| 3 |
| 4 |
| 1 |
| 6 |
=
| 3 |
| 4 |
| 3 |
| 4 |
=
| 3 |
| 4 |
=
| 3 |
| 4 |
=
| 21 |
| 2 |
11-
| 7 |
| 8 |
=11-0.875-2.125
=11-(0.875+1.125)
=11-2
=9;
12×(
| 1 |
| 4 |
| 1 |
| 6 |
| 1 |
| 3 |
=12×
| 1 |
| 4 |
| 1 |
| 6 |
| 1 |
| 3 |
=3+2-4
=1.
点评:根据题目给出的数据,找清它们各自的关系,运用合适的运算定律,能比较简便的计算出结果.
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