题目内容
小小神算手.
(1)9×
+
×2
(2)
×
+
÷
(3)3-
×
-
.
(1)9×
| 5 |
| 6 |
| 3 |
| 4 |
(2)
| 7 |
| 10 |
| 7 |
| 12 |
| 5 |
| 12 |
| 10 |
| 7 |
(3)3-
| 3 |
| 2 |
| 10 |
| 21 |
| 2 |
| 7 |
考点:分数的四则混合运算
专题:运算顺序及法则
分析:(1)先算乘法,再算加法.
(2)把除法变为乘法,运用乘法分配律简算.
(3)先算乘法,然后运用减法的运算性质简算.
(2)把除法变为乘法,运用乘法分配律简算.
(3)先算乘法,然后运用减法的运算性质简算.
解答:
解:(1)9×
+
×2
=
+
=9
(2)
×
+
÷
=
×
+
×
=
×(
+
)
=
×1
=
(3)3-
×
-
=3-
-
=3-(
+
)
=3-1
=2
| 5 |
| 6 |
| 3 |
| 4 |
=
| 15 |
| 2 |
| 3 |
| 2 |
=9
(2)
| 7 |
| 10 |
| 7 |
| 12 |
| 5 |
| 12 |
| 10 |
| 7 |
=
| 7 |
| 10 |
| 7 |
| 12 |
| 5 |
| 12 |
| 7 |
| 10 |
=
| 7 |
| 10 |
| 7 |
| 12 |
| 5 |
| 12 |
=
| 7 |
| 10 |
=
| 7 |
| 10 |
(3)3-
| 3 |
| 2 |
| 10 |
| 21 |
| 2 |
| 7 |
=3-
| 5 |
| 7 |
| 2 |
| 7 |
=3-(
| 5 |
| 7 |
| 2 |
| 7 |
=3-1
=2
点评:此题主要考查分数的四则混合运算的运算顺序和应用运算定律进行简便计算.
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