题目内容
计算,能简算的要简算.
|
2-
|
| ||||||||||||||||||
48×(
|
(0.75-
|
[1-(
|
分析:(1)把除法化成乘法,再约分计算即可,
(2)先算除法,再运用减法的运算定律进行简算,
(3)运用乘法的分配律进行简算,
(4)运用乘法的分配律进行简算,
(5)先同时求出两个小括号里的减法算式和加法算式,再算乘法,
(6)先算小括号里的减法,再算在括号里的减法,最后算除法.
(2)先算除法,再运用减法的运算定律进行简算,
(3)运用乘法的分配律进行简算,
(4)运用乘法的分配律进行简算,
(5)先同时求出两个小括号里的减法算式和加法算式,再算乘法,
(6)先算小括号里的减法,再算在括号里的减法,最后算除法.
解答:解:(1)
×0.375÷
,
=
×0.375×
,
=0.125;
(2)2-
÷
-
,
=2-
-
,
=2-(
+
),
=2-2,
=0;
(3)
×
+
×
,
=(
+
)×
,
=10×
,
=
;
(4)48×(
+
),
=48×
+48×
,
=28+6,
=34;
(5)(0.75-
)×(
+
),
=
×
,
=
;
(6)[1-(
-
)]÷
,
=[1-
]÷
,
=
÷
,
=
.
| 2 |
| 7 |
| 6 |
| 7 |
=
| 2 |
| 7 |
| 7 |
| 6 |
=0.125;
(2)2-
| 6 |
| 13 |
| 9 |
| 26 |
| 2 |
| 3 |
=2-
| 4 |
| 3 |
| 2 |
| 3 |
=2-(
| 4 |
| 3 |
| 2 |
| 3 |
=2-2,
=0;
(3)
| 10 |
| 3 |
| 5 |
| 7 |
| 20 |
| 3 |
| 5 |
| 7 |
=(
| 10 |
| 3 |
| 20 |
| 3 |
| 5 |
| 7 |
=10×
| 5 |
| 7 |
=
| 50 |
| 7 |
(4)48×(
| 7 |
| 12 |
| 1 |
| 8 |
=48×
| 7 |
| 12 |
| 1 |
| 8 |
=28+6,
=34;
(5)(0.75-
| 5 |
| 16 |
| 2 |
| 7 |
| 1 |
| 14 |
=
| 7 |
| 16 |
| 5 |
| 14 |
=
| 5 |
| 32 |
(6)[1-(
| 3 |
| 4 |
| 3 |
| 8 |
| 5 |
| 29 |
=[1-
| 3 |
| 8 |
| 5 |
| 29 |
=
| 5 |
| 8 |
| 5 |
| 29 |
=
| 29 |
| 8 |
点评:考查了分数、小数四则混合运算的顺序,注意灵活运用运算定律进行简算.
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