题目内容
脱式计算.(能简算的要简算)
÷[
-(
+
)]
÷
-
÷
24×
+75÷5+20%
(0.75-
)×(
+
)
| 4 |
| 9 |
| 5 |
| 6 |
| 2 |
| 9 |
| 1 |
| 3 |
| 5 |
| 8 |
| 1 |
| 4 |
| 1 |
| 4 |
| 5 |
| 8 |
24×
| 1 |
| 5 |
(0.75-
| 5 |
| 16 |
| 2 |
| 9 |
| 4 |
| 3 |
分析:算式(1)(2)(4)根据四则混合运算的运算顺序计算即可:先算乘除,再算加减,有括号的要先算括号里面的.
算式(3)可将式中除法算式根据分数除法的计算法则变为乘法算式后,再根据乘法分配律进行计算.
算式(3)可将式中除法算式根据分数除法的计算法则变为乘法算式后,再根据乘法分配律进行计算.
解答:解:(1)
÷[
-(
+
)]
=
÷[
-
],
=
÷
,
=
;
(2)
÷
-
÷
=
×4-
×
,
=
-
,
=
;
(3)24×
+75÷5+20%
=24×
+75×
+
,
=(24+75+1)×
,
=100×
,
=20;
(4)(0.75-
)×(
+
),
=(
-
)×
,
=
×
,
=
.
| 4 |
| 9 |
| 5 |
| 6 |
| 2 |
| 9 |
| 1 |
| 3 |
=
| 4 |
| 9 |
| 5 |
| 6 |
| 5 |
| 9 |
=
| 4 |
| 9 |
| 5 |
| 18 |
=
| 8 |
| 5 |
(2)
| 5 |
| 8 |
| 1 |
| 4 |
| 1 |
| 4 |
| 5 |
| 8 |
=
| 5 |
| 8 |
| 1 |
| 4 |
| 8 |
| 5 |
=
| 5 |
| 2 |
| 4 |
| 5 |
=
| 17 |
| 10 |
(3)24×
| 1 |
| 5 |
=24×
| 1 |
| 5 |
| 1 |
| 5 |
| 1 |
| 5 |
=(24+75+1)×
| 1 |
| 5 |
=100×
| 1 |
| 5 |
=20;
(4)(0.75-
| 5 |
| 16 |
| 2 |
| 9 |
| 4 |
| 3 |
=(
| 3 |
| 4 |
| 5 |
| 16 |
| 14 |
| 9 |
=
| 7 |
| 16 |
| 14 |
| 9 |
=
| 49 |
| 72 |
点评:当算式中同时含有分数、小数或百分数时,要根据式中数据的特点灵活将它们互化后再进行计算.
练习册系列答案
相关题目