题目内容
(2008?南靖县)下面各题,怎样计算简便就怎样计算.
2002-540÷36×96
7.28-(1.28+0.25)
2.25×1.8+17.5×0.18
36×(
+
-
)
÷[1-(
-
)].
2002-540÷36×96
7.28-(1.28+0.25)
2.25×1.8+17.5×0.18
36×(
2 |
9 |
7 |
12 |
1 |
4 |
7 |
15 |
4 |
5 |
2 |
3 |
分析:(1)中的540÷36可根据除法的性质变为540÷9÷4,将96拆分为6×16进行计算;
(2)可根据一个数减两个数的和等于用这个数分别减这两个数的减法性质进行计算;
(3)可将17.5×0.18根据乘法的性质变为1.75×1.8后再运用乘法分配律进行计算;
(4)可根据乘法分配律进行计算;
(5)根据四则混合运算的运算则计算即可:先算乘除,再算加减,有括号的要先算括号里面的.
(2)可根据一个数减两个数的和等于用这个数分别减这两个数的减法性质进行计算;
(3)可将17.5×0.18根据乘法的性质变为1.75×1.8后再运用乘法分配律进行计算;
(4)可根据乘法分配律进行计算;
(5)根据四则混合运算的运算则计算即可:先算乘除,再算加减,有括号的要先算括号里面的.
解答:解:(1)2002-540÷36×96
=2002-540÷9÷4×96,
=2002-60÷4×96,
=2002-15×6×16,
=2002-90×16,
=2002-1440,
=562;
(2)7.28-(1.28+0.25)
=7.28-1.28-0.25,
=6-0.25,
=5.75;
(3)2.25×1.8+17.5×0.18
=2.25×1.8+1.75×1.8,
=(2.25+1.75)×1.8,
=4×1.8,
=7.2;
(4)36×(
+
-
)
=36×
+36×
-36×
,
=8+21-9,
=20;
(5)
÷[1-(
-
)].
=
÷[1-(
-
)],
=
÷[1-
],
=
×
,
=
.
=2002-540÷9÷4×96,
=2002-60÷4×96,
=2002-15×6×16,
=2002-90×16,
=2002-1440,
=562;
(2)7.28-(1.28+0.25)
=7.28-1.28-0.25,
=6-0.25,
=5.75;
(3)2.25×1.8+17.5×0.18
=2.25×1.8+1.75×1.8,
=(2.25+1.75)×1.8,
=4×1.8,
=7.2;
(4)36×(
2 |
9 |
7 |
12 |
1 |
4 |
=36×
2 |
9 |
7 |
12 |
1 |
4 |
=8+21-9,
=20;
(5)
7 |
15 |
4 |
5 |
2 |
3 |
=
7 |
15 |
12 |
15 |
10 |
15 |
=
7 |
15 |
2 |
15 |
=
7 |
15 |
15 |
13 |
=
7 |
13 |
点评:当算式中同时含有中括号与小括号时,要先算小括号里面的,再算中括号里面的.
练习册系列答案
相关题目