题目内容
怎样算简便就怎样算
|
| 64×
| ||||||||||||||||
24×
| (
|
|
考点:整数、分数、小数、百分数四则混合运算,运算定律与简便运算
专题:运算顺序及法则,运算定律及简算
分析:(1)把除法变为乘法,运用乘法分配律简算;
(2)先算小括号内的,再算中括号内的,最后算括号外的;
(3)把64看作65-1,运用乘法分配律简算;
(4)运用乘法结合律简算;
(5)(6)运用乘法分配律简算.
(2)先算小括号内的,再算中括号内的,最后算括号外的;
(3)把64看作65-1,运用乘法分配律简算;
(4)运用乘法结合律简算;
(5)(6)运用乘法分配律简算.
解答:
解:(1)
×
+
÷6
=
×
+
×
=(
+
)×
=1×
=
(2)
÷[
×(
-
)]
=
÷[
×
]
=
÷
=
×4
=
(3)64×
=(65-1)×
=65×
-
=17-
=16
(4)24×
×
=24×(
×
)
=24×
=10
(5)(
+
)×24
=
×24+
×24
=16+4
=20
(6)
×99+
=
×(99+1)
=
×100
=16
| 7 |
| 10 |
| 1 |
| 6 |
| 3 |
| 10 |
=
| 7 |
| 10 |
| 1 |
| 6 |
| 3 |
| 10 |
| 1 |
| 6 |
=(
| 7 |
| 10 |
| 3 |
| 10 |
| 1 |
| 6 |
=1×
| 1 |
| 6 |
=
| 1 |
| 6 |
(2)
| 9 |
| 32 |
| 4 |
| 3 |
| 7 |
| 16 |
| 1 |
| 4 |
=
| 9 |
| 32 |
| 4 |
| 3 |
| 3 |
| 16 |
=
| 9 |
| 32 |
| 1 |
| 4 |
=
| 9 |
| 32 |
=
| 9 |
| 8 |
(3)64×
| 17 |
| 65 |
=(65-1)×
| 17 |
| 65 |
=65×
| 17 |
| 65 |
| 17 |
| 65 |
=17-
| 17 |
| 65 |
=16
| 48 |
| 65 |
(4)24×
| 5 |
| 7 |
| 7 |
| 12 |
=24×(
| 5 |
| 7 |
| 7 |
| 12 |
=24×
| 5 |
| 12 |
=10
(5)(
| 2 |
| 3 |
| 1 |
| 6 |
=
| 2 |
| 3 |
| 1 |
| 6 |
=16+4
=20
(6)
| 4 |
| 25 |
| 4 |
| 25 |
=
| 4 |
| 25 |
=
| 4 |
| 25 |
=16
点评:考查了运算定律与简便运算,四则混合运算.注意运算顺序和运算法则,灵活运用所学的运算定律简便计算.
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