题目内容
| 计算下面各题,简算的要简算: 6×(1-
|
37+18×37+19×63 | 1÷28×91-73×
| ||||||
| [4.8-0.24÷(5-4.76)]÷3.8 | (1-
|
分析:(1)先算出小括号里面的减法,再运用乘法分配律简算;
(2)先把37+18×37运用乘法分配律简算,算出后再一次运用乘法分配律;
(3)把除法变成乘法,再运用乘法分配律简算;
(4)先算小括号里面的减法,再算中括号里面的除法,然后算中括号里面的减法,最后算括号外的除法;
(5)现同时运算两个小括号里面的,再把中括号里面的按照从左到右的顺序计算,最后算括号外的除法.
(2)先把37+18×37运用乘法分配律简算,算出后再一次运用乘法分配律;
(3)把除法变成乘法,再运用乘法分配律简算;
(4)先算小括号里面的减法,再算中括号里面的除法,然后算中括号里面的减法,最后算括号外的除法;
(5)现同时运算两个小括号里面的,再把中括号里面的按照从左到右的顺序计算,最后算括号外的除法.
解答:解:(1)6×(1-
)+0.75×5
,
=6×
+0.75×5
,
=6×
+
×
,
=(6+
)×
,
=
×
,
=
;
(2)37+18×37+19×63,
=(1+18)×37+19×63,
=19×37+19×63,
=19×(37+63),
=19×100,
=1900;
(3)1÷28×91-73×
-17÷28,
=
×91-73×
-17×
,
=
×(91-73-17),
=
×1,
=
;
(4)[4.8-0.24÷(5-4.76)]÷3.8,
=[4.8-0.24÷0.24]÷3.8,
=[4.8-1]÷3.8,
=3.8÷3.8,
=1;
(5)(1-
)÷[
÷6÷(1+
)],
=
÷[
÷6÷
],
=
÷[
×
],
=
÷
,
=
.
| 1 |
| 4 |
| 2 |
| 5 |
=6×
| 3 |
| 4 |
| 2 |
| 5 |
=6×
| 3 |
| 4 |
| 3 |
| 4 |
| 27 |
| 5 |
=(6+
| 27 |
| 5 |
| 3 |
| 4 |
=
| 57 |
| 5 |
| 3 |
| 4 |
=
| 171 |
| 20 |
(2)37+18×37+19×63,
=(1+18)×37+19×63,
=19×37+19×63,
=19×(37+63),
=19×100,
=1900;
(3)1÷28×91-73×
| 1 |
| 28 |
=
| 1 |
| 28 |
| 1 |
| 28 |
| 1 |
| 28 |
=
| 1 |
| 28 |
=
| 1 |
| 28 |
=
| 1 |
| 28 |
(4)[4.8-0.24÷(5-4.76)]÷3.8,
=[4.8-0.24÷0.24]÷3.8,
=[4.8-1]÷3.8,
=3.8÷3.8,
=1;
(5)(1-
| 2 |
| 3 |
| 2 |
| 3 |
| 3 |
| 5 |
=
| 1 |
| 3 |
| 2 |
| 3 |
| 8 |
| 5 |
=
| 1 |
| 3 |
| 1 |
| 9 |
| 5 |
| 8 |
=
| 1 |
| 3 |
| 5 |
| 72 |
=
| 24 |
| 5 |
点评:1.一个算式里,如果含有两级运算,要先做第二级运算,后做第一级运算.
2.一个算式里,如果有括号,要先算小括号里的,再算中括号里面的,主要运用运算定律简算.
2.一个算式里,如果有括号,要先算小括号里的,再算中括号里面的,主要运用运算定律简算.
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