题目内容
能用简算的用简算
-
-
×
+
×
(
-
)÷
9÷
-
÷
.
| 7 |
| 4 |
| 1 |
| 10 |
| 9 |
| 10 |
| 7 |
| 13 |
| 4 |
| 9 |
| 7 |
| 13 |
| 5 |
| 9 |
(
| 6 |
| 7 |
| 3 |
| 5 |
| 9 |
| 5 |
| 6 |
| 7 |
| 7 |
| 6 |
| 1 |
| 9 |
分析:算式一可据结合律进行简算,算式二三四可据分配律进行简算.
解答:解:(1)
-
-
,
=
-(
+
),
=
-1,
=
;
(2)
×
+
×
,
=
×(
+
),
=
×1,
=
;
(3)(
-
)÷
,
=
×
-
×
,
=
-
,
=
;
(4)9÷
-
÷
,
=9×
-
×9,
=(
-
)×9,
=0×9,
=0.
| 7 |
| 4 |
| 1 |
| 10 |
| 9 |
| 10 |
=
| 7 |
| 4 |
| 1 |
| 10 |
| 9 |
| 10 |
=
| 7 |
| 4 |
=
| 3 |
| 4 |
(2)
| 7 |
| 13 |
| 4 |
| 9 |
| 7 |
| 13 |
| 5 |
| 9 |
=
| 7 |
| 13 |
| 4 |
| 9 |
| 5 |
| 9 |
=
| 7 |
| 13 |
=
| 7 |
| 13 |
(3)(
| 6 |
| 7 |
| 3 |
| 5 |
| 9 |
| 5 |
=
| 6 |
| 7 |
| 5 |
| 9 |
| 3 |
| 5 |
| 5 |
| 9 |
=
| 10 |
| 21 |
| 1 |
| 3 |
=
| 1 |
| 7 |
(4)9÷
| 6 |
| 7 |
| 7 |
| 6 |
| 1 |
| 9 |
=9×
| 7 |
| 6 |
| 7 |
| 6 |
=(
| 7 |
| 6 |
| 7 |
| 6 |
=0×9,
=0.
点评:完成本题要认真分析式中数据,运用合适的运算定律进行简算.
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