题目内容
怎样简便就怎样算.
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分析:(1)
÷7+
×
,把除数转化为乘它的倒数,再运用乘法分配律进行简算;
(2)
×
+
÷
,根据分数四则混合运算的顺序,按照分数四则运算的计算法则进行计算;
(3)(
+
+
)×24,运用乘法分配律进行简算;
(4)
-
÷
,根据分数四则混合运算的顺序,按照分数四则运算的计算法则进行计算;
(5)
+
-
+
,根据加、减法的运算性质和加法结合律进行简算;
(6)
÷
÷
.把除数转化为乘它的倒数,然后按照分数乘法的计算法则进行计算.
| 8 |
| 13 |
| 1 |
| 7 |
| 6 |
| 13 |
(2)
| 1 |
| 2 |
| 2 |
| 5 |
| 9 |
| 10 |
| 9 |
| 20 |
(3)(
| 1 |
| 2 |
| 2 |
| 3 |
| 3 |
| 4 |
(4)
| 9 |
| 10 |
| 5 |
| 8 |
| 5 |
| 6 |
(5)
| 8 | ||||
|
| 7 |
| 15 |
| 8 | ||||
|
| 7 |
| 15 |
(6)
| 1 |
| 2 |
| 21 |
| 23 |
| 23 |
| 63 |
解答:解:(1)
÷7+
×
,
×
+
×
,
=(
+
)×
,
=
×
,
=
;
(2)
×
+
÷
,
=
+
×
,
=
+2,
=2
;
(3)(
+
+
)×24,
=24×
+24×
+24×
,
=12+16+18,
=46;
(4)
-
÷
,
=
-
×
,
=
-
,
-
,
=
;
(5)
+
-
+
,
=
-
+(
+
),
=0+
,
=
;
(6)
÷
÷
.
=
×
×
,
=
,
=1
.
| 8 |
| 13 |
| 1 |
| 7 |
| 6 |
| 13 |
| 8 |
| 13 |
| 1 |
| 7 |
| 1 |
| 7 |
| 6 |
| 13 |
=(
| 8 |
| 13 |
| 6 |
| 13 |
| 1 |
| 7 |
=
| 14 |
| 13 |
| 1 |
| 7 |
=
| 2 |
| 13 |
(2)
| 1 |
| 2 |
| 2 |
| 5 |
| 9 |
| 10 |
| 9 |
| 20 |
=
| 1 |
| 5 |
| 9 |
| 10 |
| 20 |
| 9 |
=
| 1 |
| 5 |
=2
| 1 |
| 5 |
(3)(
| 1 |
| 2 |
| 2 |
| 3 |
| 3 |
| 4 |
=24×
| 1 |
| 2 |
| 2 |
| 3 |
| 3 |
| 4 |
=12+16+18,
=46;
(4)
| 9 |
| 10 |
| 5 |
| 8 |
| 5 |
| 6 |
=
| 9 |
| 10 |
| 5 |
| 8 |
| 6 |
| 5 |
=
| 9 |
| 10 |
| 3 |
| 4 |
| 18 |
| 20 |
| 15 |
| 20 |
=
| 3 |
| 20 |
(5)
| 8 | ||||
|
| 7 |
| 15 |
| 8 | ||||
|
| 7 |
| 15 |
=
| 8 |
| 9 |
| 8 |
| 9 |
| 7 |
| 15 |
| 7 |
| 15 |
=0+
| 14 |
| 15 |
=
| 14 |
| 15 |
(6)
| 1 |
| 2 |
| 21 |
| 23 |
| 23 |
| 63 |
=
| 1 |
| 2 |
| 23 |
| 21 |
| 63 |
| 23 |
=
| 3 |
| 2 |
=1
| 1 |
| 2 |
点评:此题考查的目的是使学生掌握分数四则混合运算的顺序和它们的计算法则,并且能够灵活选择简便方法进行计算.
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