题目内容
下面各题,怎样简便就怎样计算.
8-
+14.2-
; 24×(
+
-
); 97×
; 75%×25+75×
.
8-
7 |
18 |
11 |
18 |
1 |
4 |
1 |
6 |
1 |
3 |
7 |
96 |
3 |
4 |
分析:(1)运用加法交换律与结合律简算以及减法的性质简算;
(2)运用乘法分配律简算;
(3)把97看作96+1,运用乘法分配律简算简算;
(4)把百分数化为分数,运用乘法分配律简算.
(2)运用乘法分配律简算;
(3)把97看作96+1,运用乘法分配律简算简算;
(4)把百分数化为分数,运用乘法分配律简算.
解答:解:(1)8-
+14.2-
=(8+14.2)-(
+
)
=22.2-1
=21.2;
(2)24×(
+
-
)
=24×
+24×
-24×
=6+4-8
=2;
(3)97×
=(96+1)×
=96×
+
=7+
=7
;
(4)75%×25+75×
=
×25+75×
=
×(25+75)
=
×100
=75.
7 |
18 |
11 |
18 |
=(8+14.2)-(
7 |
18 |
11 |
18 |
=22.2-1
=21.2;
(2)24×(
1 |
4 |
1 |
6 |
1 |
3 |
=24×
1 |
4 |
1 |
6 |
1 |
3 |
=6+4-8
=2;
(3)97×
7 |
96 |
=(96+1)×
7 |
96 |
=96×
7 |
96 |
7 |
96 |
=7+
7 |
96 |
=7
7 |
96 |
(4)75%×25+75×
3 |
4 |
=
3 |
4 |
3 |
4 |
=
3 |
4 |
=
3 |
4 |
=75.
点评:仔细注意观察题目中数字构成的特点和规律,运用运算定律或运算技巧,进行简便计算.
练习册系列答案
相关题目