题目内容
(2012?康县模拟)脱式计算(能用简便方法的用简便方法计算)
[(
-
)+
]÷
61
-15.37+38
-34.63
23-
×
÷
5.8×99-4.2
10.6-(6.3+0.125÷12.5%)
[(
7 |
16 |
1 |
4 |
15 |
16 |
1 |
2 |
61
3 |
4 |
1 |
4 |
23-
8 |
9 |
3 |
8 |
1 |
27 |
5.8×99-4.2
10.6-(6.3+0.125÷12.5%)
分析:(1)(3)(5)依据四则运算计算方法解答,
(2)运用加法交换律和加法减法性质解答,
(4)先运用乘法分配律,再根据减法性质解答.
(2)运用加法交换律和加法减法性质解答,
(4)先运用乘法分配律,再根据减法性质解答.
解答:解:(1)[(
-
)+
]÷
,
=[
+
]÷
,
=
÷
,
=2.25;
(2)61
-15.37+38
-34.63,
=(61
+38
)-(15.37+34.63),
=100-50,
=50;
(3)23-
×
÷
,
=23-
÷
,
=23-9,
=14;
(4)5.8×99-4.2,
=5.8×(100-1)-4.2,
=580-5.8-4.2,
=580-(5.8+4.2),
=580-10,
=570;
(5)10.6-(6.3+0.125÷12.5%),
=10.6-(6.3+1),
=10.6-7.3,
=3.3.
7 |
16 |
1 |
4 |
15 |
16 |
1 |
2 |
=[
3 |
16 |
15 |
16 |
1 |
2 |
=
18 |
16 |
1 |
2 |
=2.25;
(2)61
3 |
4 |
1 |
4 |
=(61
3 |
4 |
1 |
4 |
=100-50,
=50;
(3)23-
8 |
9 |
3 |
8 |
1 |
27 |
=23-
3 |
9 |
1 |
27 |
=23-9,
=14;
(4)5.8×99-4.2,
=5.8×(100-1)-4.2,
=580-5.8-4.2,
=580-(5.8+4.2),
=580-10,
=570;
(5)10.6-(6.3+0.125÷12.5%),
=10.6-(6.3+1),
=10.6-7.3,
=3.3.
点评:本题主要考查学生合理运用四则运算法则以及运算定律进行简便计算的能力.
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