题目内容
计算下面各题,能简便运算的要简便运算 8.54-1.47-2.53 |
12×(
| ||||||||||
17.28-(7.28+
|
|
分析:(1)根据连减的简便方法计算即可;
(2)根据乘法分配律简便计算;
(3)去括号简算计算;
(4)先算小括号里的加法,再算中括号里的除法,再后算括号外面的除法.
(2)根据乘法分配律简便计算;
(3)去括号简算计算;
(4)先算小括号里的加法,再算中括号里的除法,再后算括号外面的除法.
解答:解:(1)8.54-1.47-2.53,
=8.54-(1.47+2.53),
=8.54-4,
=4.54;
(2)12×(
+
-
),
=12×
+12×
-12×
,
=3+4-2,
=5;
(3)17.28-(7.28+
),
=17.28-7.28-0.75,
=10-0.75,
=9.25;
(4)
÷[(
+
)÷
],
=
÷[
÷
],
=
×
,
=
.
=8.54-(1.47+2.53),
=8.54-4,
=4.54;
(2)12×(
1 |
4 |
1 |
3 |
1 |
6 |
=12×
1 |
4 |
1 |
3 |
1 |
6 |
=3+4-2,
=5;
(3)17.28-(7.28+
3 |
4 |
=17.28-7.28-0.75,
=10-0.75,
=9.25;
(4)
7 |
8 |
1 |
4 |
1 |
3 |
1 |
2 |
=
7 |
8 |
7 |
12 |
1 |
2 |
=
7 |
8 |
6 |
7 |
=
3 |
4 |
点评:此题是考查四则混合运算,要仔细观察算式的特点,灵活运用一些定律进行简便计算.
练习册系列答案
相关题目