题目内容
57.26-(5.26-1.5) | 64×1.25×2.5 | ||||||||||||||
(
|
4.8×3.9+6.1×4
| ||||||||||||||
12×(
|
(
| ||||||||||||||
34.5×9.23-34.5+1.77×34.5 | 2-
|
分析:(1)去掉括号,根据减去两个数的差,等于减去被减数、加上减数来计算;
(2)把64拆分为8×8的形式,然后运用乘法分配律进行简算;
(3)根据除以一个分数,等于乘这个分数的倒数,把除法转化为乘法,然后运用乘法分配律进率简算;
(4)运用乘法分配律,提取4.8进行简算;
(5)运用乘法分配律,去括号,进行简算;
(6)根据分数四则混合运算的运算顺序进行计算即可;
(7)运用乘法分配律进行简算;
(8)根据分数四则混合运算的运算顺序,先算除法,进而根据减法的性质进行简算.
(2)把64拆分为8×8的形式,然后运用乘法分配律进行简算;
(3)根据除以一个分数,等于乘这个分数的倒数,把除法转化为乘法,然后运用乘法分配律进率简算;
(4)运用乘法分配律,提取4.8进行简算;
(5)运用乘法分配律,去括号,进行简算;
(6)根据分数四则混合运算的运算顺序进行计算即可;
(7)运用乘法分配律进行简算;
(8)根据分数四则混合运算的运算顺序,先算除法,进而根据减法的性质进行简算.
解答:解:(1)57.26-(5.26-1.5),
=57.26-5.26+1.5,
=52+1.5,
=53.5;
(2)64×1.25×2.5,
=8×8×1.25×2.5,
=(8×1.25)×(8×2.5),
=10×20,
=200;
(3)(
+
)÷
,
=(
+
)×
,
=
×
+
×
,
=
+1,
=4
;
(4)4.8×3.9+6.1×4
,
=(3.9+6.1)×4.8,
=10×4.8,
=48;
(5)12×(
+
-
),
=12×
+12×
-12×
,
=2+3-4,
=1;
(6)(
+
)÷
+
,
=(
+
)×
+
,
=
×
+
,
=
+
,
=1
;
(7)34.5×9.23-34.5+1.77×34.5,
=34.5×(9.23-1+1.77),
=34.5×10,
=345;
(8)2-
÷
-
,
=2-
×
-
,
=2-
-
,
=2-(
+
),
=0.
=57.26-5.26+1.5,
=52+1.5,
=53.5;
(2)64×1.25×2.5,
=8×8×1.25×2.5,
=(8×1.25)×(8×2.5),
=10×20,
=200;
(3)(
4 |
9 |
2 |
15 |
2 |
15 |
=(
4 |
9 |
2 |
15 |
15 |
2 |
=
4 |
9 |
15 |
2 |
2 |
15 |
15 |
2 |
=
10 |
3 |
=4
1 |
3 |
(4)4.8×3.9+6.1×4
4 |
5 |
=(3.9+6.1)×4.8,
=10×4.8,
=48;
(5)12×(
1 |
6 |
1 |
4 |
1 |
3 |
=12×
1 |
6 |
1 |
4 |
1 |
3 |
=2+3-4,
=1;
(6)(
1 |
4 |
4 |
5 |
7 |
3 |
7 |
10 |
=(
1 |
4 |
4 |
5 |
3 |
7 |
7 |
10 |
=
21 |
20 |
3 |
7 |
7 |
10 |
=
9 |
20 |
14 |
20 |
=1
3 |
20 |
(7)34.5×9.23-34.5+1.77×34.5,
=34.5×(9.23-1+1.77),
=34.5×10,
=345;
(8)2-
6 |
13 |
9 |
26 |
2 |
3 |
=2-
6 |
13 |
26 |
9 |
2 |
3 |
=2-
4 |
3 |
2 |
3 |
=2-(
4 |
3 |
2 |
3 |
=0.
点评:本题考查了整数、小数、分数的四则混合运算顺序,同时也考查了运算定律的运用.
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