题目内容
用自己喜欢的方法计算
(
|
25×(
|
|
|
分析:(1)先把除法变成乘法,再运用乘法分配律简算;
(2)运用乘法交换律和结合律简算;
(3)先算乘法,再按照从左到右的顺序计算加法;
(4)先算小括号里面的减法,再按照从左到右的顺序计算加法.
(2)运用乘法交换律和结合律简算;
(3)先算乘法,再按照从左到右的顺序计算加法;
(4)先算小括号里面的减法,再按照从左到右的顺序计算加法.
解答:解:(1)(
+
)÷
,
=(
+
)×24,
=
×24+
×24,
=8+6,
=14;
(2)25×(
×40%)×
,
=(25×40%)×(
×
),
=10×1,
=10;
(3)
+
+
×
,
=
+
+
,
=
+
,
=
;
(4)
+(1-
)+
,
=
+
+
,
=
+
,
=
.
1 |
3 |
1 |
4 |
1 |
24 |
=(
1 |
3 |
1 |
4 |
=
1 |
3 |
1 |
4 |
=8+6,
=14;
(2)25×(
9 |
7 |
7 |
9 |
=(25×40%)×(
9 |
7 |
7 |
9 |
=10×1,
=10;
(3)
5 |
8 |
5 |
7 |
2 |
5 |
1 |
4 |
=
5 |
8 |
5 |
7 |
1 |
10 |
=
75 |
56 |
1 |
10 |
=
403 |
280 |
(4)
1 |
50 |
2 |
5 |
3 |
20 |
=
1 |
50 |
3 |
5 |
3 |
20 |
=
31 |
50 |
3 |
20 |
=
77 |
100 |
点评:本题考查了四则混合运算,注意运算顺序和运算法则,灵活运用所学的运算定律进行简便计算.
练习册系列答案
相关题目