题目内容
(2009?平遥县模拟)
下面各题怎样简便就怎样算
|
|
|
24×(
|
分析:(1)按运算顺序进行计算,先算括号内的,再算括号外的,在计算过程中,注意通分和约分;
(2)按运算顺序进行计算,先算括号内的,再算括号外的,在计算过程中,注意通分和约分;
(3)把除法改为乘法,运用乘法分配律的逆运算简算;
(4)运用乘法分配律进行简算.
(2)按运算顺序进行计算,先算括号内的,再算括号外的,在计算过程中,注意通分和约分;
(3)把除法改为乘法,运用乘法分配律的逆运算简算;
(4)运用乘法分配律进行简算.
解答:解:(1)
×(
+
)+
,
=
×(
+
)+
,
=
×
+
,
=
+
,
=
,
=2;
(2)
-(
-
)÷
,
=
-(
-
)÷
,
=
-
×
,
=
-
,
=
-
,
=
;
(3)
×
+
÷
,
=
×
+
×
,
=(
+
)×
,
=1×
,
=
;
(4)24×(
+
),
=24×
+24×
,
=18+20,
=38.
| 15 |
| 16 |
| 5 |
| 6 |
| 1 |
| 2 |
| 3 |
| 4 |
=
| 15 |
| 16 |
| 5 |
| 6 |
| 3 |
| 6 |
| 3 |
| 4 |
=
| 15 |
| 16 |
| 8 |
| 6 |
| 3 |
| 4 |
=
| 5 |
| 4 |
| 3 |
| 4 |
=
| 8 |
| 4 |
=2;
(2)
| 1 |
| 2 |
| 3 |
| 4 |
| 3 |
| 5 |
| 7 |
| 10 |
=
| 1 |
| 2 |
| 15 |
| 20 |
| 12 |
| 20 |
| 7 |
| 10 |
=
| 1 |
| 2 |
| 3 |
| 20 |
| 10 |
| 7 |
=
| 1 |
| 2 |
| 3 |
| 14 |
=
| 7 |
| 14 |
| 3 |
| 14 |
=
| 2 |
| 7 |
(3)
| 2 |
| 3 |
| 2 |
| 7 |
| 2 |
| 3 |
| 7 |
| 5 |
=
| 2 |
| 3 |
| 2 |
| 7 |
| 2 |
| 3 |
| 5 |
| 7 |
=(
| 2 |
| 7 |
| 5 |
| 7 |
| 2 |
| 3 |
=1×
| 2 |
| 3 |
=
| 2 |
| 3 |
(4)24×(
| 3 |
| 4 |
| 5 |
| 6 |
=24×
| 3 |
| 4 |
| 5 |
| 6 |
=18+20,
=38.
点评:此题考查了学生对分数四则混合运算顺序的掌握,以及运用运算定律进行简算的能力.
练习册系列答案
相关题目