题目内容
计算下面各题
|
|
| |||||||||||||
9×
|
|
分析:根据分数乘法的运算法则:分子相乘的积做分子,分母相乘的积做分母进行求解;其中9×
×
按照从左到右的顺序求解;
+
×
×
×
先从左到右的顺序计算乘法,再算加法.
| 2 |
| 9 |
| 5 |
| 12 |
| 1 |
| 6 |
| 5 |
| 7 |
| 14 |
| 25 |
| 5 |
| 12 |
| 14 |
| 15 |
解答:解:(1)
×
,
=
=
;
(2)
×
,
=
,
=
;
(3)
×
,

=
;
(4)9×
×
,
=2×
,
=
;
(5)
+
×
×
×
,
=
+
×
×
,
=
+
×
,
=
+
,
=
.
| 7 |
| 15 |
| 3 |
| 14 |
=
=
| 1 |
| 10 |
(2)
| 9 |
| 4 |
| 11 |
| 5 |
=
| 9×11 |
| 4×5 |
=
| 99 |
| 20 |
(3)
| 29 |
| 33 |
| 44 |
| 87 |
=
| 4 |
| 9 |
(4)9×
| 2 |
| 9 |
| 5 |
| 12 |
=2×
| 5 |
| 12 |
=
| 5 |
| 6 |
(5)
| 1 |
| 6 |
| 5 |
| 7 |
| 14 |
| 25 |
| 5 |
| 12 |
| 14 |
| 15 |
=
| 1 |
| 6 |
| 2 |
| 5 |
| 5 |
| 12 |
| 14 |
| 15 |
=
| 1 |
| 6 |
| 1 |
| 6 |
| 14 |
| 15 |
=
| 1 |
| 6 |
| 7 |
| 45 |
=
| 29 |
| 90 |
点评:本题考查了分数乘法的计算方法,计算时要细心,把结果化成最简分数.
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