题目内容
怎样算简便就怎样算.
×7÷
(
+
)×
÷
+
÷
.
| 1 |
| 3 |
| 2 |
| 3 |
(
| 7 |
| 8 |
| 7 |
| 6 |
| 4 |
| 21 |
| 1 |
| 4 |
| 5 |
| 8 |
| 3 |
| 4 |
| 5 |
| 8 |
分析:(1)把除法改为乘法,约分即可;
(2)运用乘法分配律简算;
(3)运用除法的性质简算.
(2)运用乘法分配律简算;
(3)运用除法的性质简算.
解答:解:(1)
×7÷
,
=
×7×
,
=
;
(2)(
+
)×
,
=
×
+
×
,
=
+
,
=
;
(3)
÷
+
÷
,
=(
+
)÷
,
=1÷
,
=
.
| 1 |
| 3 |
| 2 |
| 3 |
=
| 1 |
| 3 |
| 3 |
| 2 |
=
| 7 |
| 2 |
(2)(
| 7 |
| 8 |
| 7 |
| 6 |
| 4 |
| 21 |
=
| 7 |
| 8 |
| 4 |
| 21 |
| 7 |
| 6 |
| 4 |
| 21 |
=
| 1 |
| 6 |
| 2 |
| 9 |
=
| 7 |
| 18 |
(3)
| 1 |
| 4 |
| 5 |
| 8 |
| 3 |
| 4 |
| 5 |
| 8 |
=(
| 1 |
| 4 |
| 3 |
| 4 |
| 5 |
| 8 |
=1÷
| 5 |
| 8 |
=
| 8 |
| 5 |
点评:完成此题,注意乘除法的转化,以及运用运算定律进行简算.
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