题目内容
计算下面各题. ①
|
②1.05×(3.8-0.8)÷6.3 | ||||||||||||||
③
|
④
|
分析:①把除以变为乘以,然后再运用乘法的分配律进行计算.
②④按照小数、分数四则混合运算的剩下进行计算,先计算括号内部的,再就是括号外面的.
③把3÷4转化成
,再运用乘法的分配律进行计算即可.
②④按照小数、分数四则混合运算的剩下进行计算,先计算括号内部的,再就是括号外面的.
③把3÷4转化成
3 |
4 |
解答:解:①
÷5+
÷2,
=
×
+
×
,
=
×(
+
),
=
×
,
=
;
②1.05×(3.8-0.8)÷6.3,
=1.05×3÷6.3,
=3.15÷6.3,
=0.5;
③
×
+3÷4×
,
=
×
+
×
,
=
×(
+
),
=
×1,
=
;
④
+
÷
×
,
=④
+
×
×
,
=
+
×
,
=
+
,
=
,
=1
;
7 |
8 |
7 |
8 |
=
7 |
8 |
1 |
5 |
7 |
8 |
1 |
2 |
=
7 |
8 |
2 |
10 |
5 |
10 |
=
7 |
8 |
7 |
10 |
=
49 |
80 |
②1.05×(3.8-0.8)÷6.3,
=1.05×3÷6.3,
=3.15÷6.3,
=0.5;
③
1 |
4 |
2 |
5 |
2 |
5 |
=
1 |
4 |
2 |
5 |
3 |
4 |
2 |
5 |
=
2 |
5 |
1 |
4 |
3 |
4 |
=
2 |
5 |
=
2 |
5 |
④
3 |
4 |
3 |
7 |
9 |
28 |
2 |
5 |
=④
3 |
4 |
3 |
7 |
28 |
9 |
2 |
5 |
=
3 |
4 |
4 |
3 |
2 |
5 |
=
45 |
60 |
32 |
60 |
=
77 |
60 |
=1
7 |
60 |
点评:根据式子中的数值,选择合适的运算定律进行解答即可.
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