题目内容
脱式计算,能简便的用简便方法计算 (1)0.4×580-195÷6.5 |
(2)7.6÷1.25÷8 | (3)(
| ||||||||||||||||
(4)
|
(5)18.64-(
|
(6)
|
分析:(1)先算乘除,再算减法;
(2)运用除法的性质简算;
(3)先算括号内的,再算括号外的除法,最后算减法;
(4)把除法改为乘法,运用乘法分配律简算;
(5)运用减法的性质以及加法交换律与结合律简算;
(6)先算小括号内的,再算中括号内的,最后算括号外的.
(2)运用除法的性质简算;
(3)先算括号内的,再算括号外的除法,最后算减法;
(4)把除法改为乘法,运用乘法分配律简算;
(5)运用减法的性质以及加法交换律与结合律简算;
(6)先算小括号内的,再算中括号内的,最后算括号外的.
解答:解:(1)0.4×580-195÷6.5,
=232-30,
=202;
(2)7.6÷1.25÷8,
=7.6÷(1.25×8),
=7.6÷10,
=0.76;
(3)(
+
)÷
-
,
=
×
-
,
=
-
,
=
;
(4)
÷
-
×
,
=
×
-
×
,
=
×(
-
),
=
×
,
=
;
(5)18.64-(
+4.64),
=18.64-
-4.64,
=(18.64-4.64)-
,
=14-
,
=13
;
(6)
÷[8×(
-
)],
=
÷[8×(-
)],
=
÷(-2),
=-
×
,
=-
.
=232-30,
=202;
(2)7.6÷1.25÷8,
=7.6÷(1.25×8),
=7.6÷10,
=0.76;
(3)(
2 |
7 |
1 |
2 |
3 |
2 |
5 |
21 |
=
11 |
14 |
2 |
3 |
5 |
21 |
=
11 |
21 |
5 |
21 |
=
2 |
7 |
(4)
5 |
6 |
4 |
5 |
4 |
5 |
5 |
6 |
=
5 |
6 |
5 |
4 |
4 |
5 |
5 |
6 |
=
5 |
6 |
5 |
4 |
4 |
5 |
=
5 |
6 |
9 |
20 |
=
3 |
8 |
(5)18.64-(
2 |
9 |
=18.64-
2 |
9 |
=(18.64-4.64)-
2 |
9 |
=14-
2 |
9 |
=13
7 |
9 |
(6)
9 |
16 |
1 |
2 |
3 |
4 |
=
9 |
16 |
1 |
4 |
=
9 |
16 |
=-
9 |
16 |
1 |
2 |
=-
9 |
32 |
点评:此题考查了四则混合运算,注意运算顺序和运算法则,灵活运用所学的运算定律进行简便计算.
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