题目内容
(2005?龙湖区)脱式计算.(能简算的要简算)
1840-725÷25×16
-
-
16.4+3.5+83.6+166.5
(
+
)×
-
59+59×13+14×41
36÷[(
-
)×3].
1840-725÷25×16
27 |
8 |
8 |
17 |
9 |
17 |
16.4+3.5+83.6+166.5
(
8 |
9 |
4 |
3 |
3 |
4 |
1 |
4 |
59+59×13+14×41
36÷[(
5 |
6 |
1 |
3 |
分析:(1)1840-725÷25×16,再计算1840-29×16时,把29看作30-1,计算起来较简便;
(2)
-
-
,运用减法的性质简算,同时注意运算符号的变化;
(3)16.4+3.5+83.6+166.5,运用加法交换律和结合律简算;
(4)(
+
)×
-
,在计算(
+
)×
时,运用乘法分配律简算;
(5)59+59×13+14×41,此题运用乘法分配律的逆运算简算;
(6)36÷[(
-
)×3],先算(
-
)×3,运用乘法分配律简算,然后算括号外的.
(2)
27 |
8 |
8 |
17 |
9 |
17 |
(3)16.4+3.5+83.6+166.5,运用加法交换律和结合律简算;
(4)(
8 |
9 |
4 |
3 |
3 |
4 |
1 |
4 |
8 |
9 |
4 |
3 |
3 |
4 |
(5)59+59×13+14×41,此题运用乘法分配律的逆运算简算;
(6)36÷[(
5 |
6 |
1 |
3 |
5 |
6 |
1 |
3 |
解答:解:(1)1840-725÷25×16,
=1840-29×16,
=1840-(30-1)×16,
=1840-30×16+16,
=1360+16,
=1376;
(2)
-
-
,
=
-(
+
),
=
-1,
=
,
=2
;
(3)16.4+3.5+83.6+166.5,
=(16.4+83.6)+(3.5+166.5),
=100+170,
=270;
(4)(
+
)×
-
,
=
×
+
×
-
,
=
+1-
,
=
-
+1,
=
+1,
=1
;
(5)59+59×13+14×41,
=(1+13)×59+14×41,
=14×59+14×41,
=(59+41)×14,
=100×14,
=1400;
(6)36÷[(
-
)×3],
=36÷[
×3-
×3],
=36÷
,
=36×
,
=24.
=1840-29×16,
=1840-(30-1)×16,
=1840-30×16+16,
=1360+16,
=1376;
(2)
27 |
8 |
8 |
17 |
9 |
17 |
=
27 |
8 |
8 |
17 |
9 |
17 |
=
27 |
8 |
=
19 |
8 |
=2
3 |
8 |
(3)16.4+3.5+83.6+166.5,
=(16.4+83.6)+(3.5+166.5),
=100+170,
=270;
(4)(
8 |
9 |
4 |
3 |
3 |
4 |
1 |
4 |
=
8 |
9 |
3 |
4 |
4 |
3 |
3 |
4 |
1 |
4 |
=
2 |
3 |
1 |
4 |
=
2 |
3 |
1 |
4 |
=
5 |
12 |
=1
5 |
12 |
(5)59+59×13+14×41,
=(1+13)×59+14×41,
=14×59+14×41,
=(59+41)×14,
=100×14,
=1400;
(6)36÷[(
5 |
6 |
1 |
3 |
=36÷[
5 |
6 |
1 |
3 |
=36÷
3 |
2 |
=36×
2 |
3 |
=24.
点评:此题考查学生对四则混合运算顺序的掌握情况,以及对运算定律的灵活运用能力.
练习册系列答案
相关题目