题目内容
计算下面各题(能简便计算的要简算)
|
|
1-
| ||||||||||||||||||||||
|
[
|
|
分析:(1)先计算小括号内部的,再计算括号外面的.
(2)把除法转化为乘法,在运用乘法的分配律进行计算.
(3)先把除法改写成乘法,在运用c-a-b=c-(a+b)进行计算,是运算更加简便.
(4)先计算括号内部的,再按照分数乘除法的顺序进行计算.
(5)先计算括号里面的,然后在运用乘法的分配律进行计算.
(6)先计算小括号内部的,在计算中括号内的,最后计算括号外面的.
(2)把除法转化为乘法,在运用乘法的分配律进行计算.
(3)先把除法改写成乘法,在运用c-a-b=c-(a+b)进行计算,是运算更加简便.
(4)先计算括号内部的,再按照分数乘除法的顺序进行计算.
(5)先计算括号里面的,然后在运用乘法的分配律进行计算.
(6)先计算小括号内部的,在计算中括号内的,最后计算括号外面的.
解答:解:(1)
+(
-
)÷
,
=
+(
-
)×5,
=
+
,
=
+
,
=
,
=
;
(2)
×
+
÷4,
=
×
+
×
,
=
×(
+
),
=
×1,
=
;
(3)1-
÷
-
,
=1-
×
-
,
=1-
-
,
=1-(
+
),
=1-1,
=0;
(4)
÷[
×(1-
)],
=
÷[
×
],
=
÷
,
=
×
,
=
;
(5)[
-(
-
)]÷
,
=[
-(
-
)]×
,
=[
-
]×
,
=
×
-
×
,
=
-
,
=
;
(6)
×[
÷(
+
)],
=
×[
÷(
+
)],
=
×[
×
],
=
.
| 1 |
| 3 |
| 3 |
| 4 |
| 2 |
| 3 |
| 1 |
| 5 |
=
| 1 |
| 3 |
| 9 |
| 12 |
| 8 |
| 12 |
=
| 1 |
| 3 |
| 5 |
| 12 |
=
| 4 |
| 12 |
| 5 |
| 12 |
=
| 9 |
| 12 |
=
| 3 |
| 4 |
(2)
| 3 |
| 5 |
| 1 |
| 4 |
| 2 |
| 5 |
=
| 3 |
| 5 |
| 1 |
| 4 |
| 2 |
| 5 |
| 1 |
| 4 |
=
| 1 |
| 4 |
| 3 |
| 5 |
| 2 |
| 5 |
=
| 1 |
| 4 |
=
| 1 |
| 4 |
(3)1-
| 6 |
| 11 |
| 21 |
| 22 |
| 3 |
| 7 |
=1-
| 6 |
| 11 |
| 22 |
| 21 |
| 3 |
| 7 |
=1-
| 4 |
| 7 |
| 3 |
| 7 |
=1-(
| 3 |
| 7 |
| 4 |
| 7 |
=1-1,
=0;
(4)
| 3 |
| 8 |
| 3 |
| 5 |
| 1 |
| 3 |
=
| 3 |
| 8 |
| 3 |
| 5 |
| 2 |
| 3 |
=
| 3 |
| 8 |
| 2 |
| 5 |
=
| 3 |
| 8 |
| 5 |
| 2 |
=
| 15 |
| 16 |
(5)[
| 7 |
| 10 |
| 4 |
| 5 |
| 1 |
| 3 |
| 14 |
| 15 |
=[
| 7 |
| 10 |
| 12 |
| 15 |
| 5 |
| 15 |
| 15 |
| 14 |
=[
| 7 |
| 10 |
| 7 |
| 15 |
| 15 |
| 14 |
=
| 7 |
| 10 |
| 15 |
| 14 |
| 7 |
| 15 |
| 15 |
| 14 |
=
| 3 |
| 4 |
| 1 |
| 2 |
=
| 1 |
| 4 |
(6)
| 8 |
| 9 |
| 3 |
| 4 |
| 1 |
| 3 |
| 1 |
| 5 |
=
| 8 |
| 9 |
| 3 |
| 4 |
| 5 |
| 15 |
| 3 |
| 15 |
=
| 8 |
| 9 |
| 3 |
| 4 |
| 15 |
| 8 |
=
| 5 |
| 4 |
点评:注意运算顺序和运算法则,灵活运用所学的运算律简便计算.
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