题目内容
计算下面各题,能简便的要用简便方法计算.
×(
+
)
×103-
×2-
7
+(
-
)
| 1 |
| 14 |
| 1 |
| 4 |
| 1 |
| 12 |
| 7 |
| 25 |
| 7 |
| 25 |
| 7 |
| 25 |
7
| 2 |
| 17 |
| 5 |
| 18 |
| 2 |
| 17 |
考点:运算定律与简便运算
专题:运算定律及简算
分析:①先计算括号里面的,再计算括号外面的乘法;
②根据乘法分配律简便计算;
③首先去括号,然后根据加法交换律和结合律计算;即可得解.
②根据乘法分配律简便计算;
③首先去括号,然后根据加法交换律和结合律计算;即可得解.
解答:
解:①
×(
+
)
=
×(
+
)
=
×
=
②
×103-
×2-
=
×(103-2-1)
=
×100
=28
③7
+(
-
)
=7
+
-
=(7
-
)+
=7+
=7
| 1 |
| 14 |
| 1 |
| 4 |
| 1 |
| 12 |
=
| 1 |
| 14 |
| 3 |
| 12 |
| 1 |
| 12 |
=
| 1 |
| 14 |
| 1 |
| 3 |
=
| 1 |
| 42 |
②
| 7 |
| 25 |
| 7 |
| 25 |
| 7 |
| 25 |
=
| 7 |
| 25 |
=
| 7 |
| 25 |
=28
③7
| 2 |
| 17 |
| 5 |
| 18 |
| 2 |
| 17 |
=7
| 2 |
| 17 |
| 5 |
| 18 |
| 2 |
| 17 |
=(7
| 2 |
| 17 |
| 2 |
| 17 |
| 5 |
| 18 |
=7+
| 5 |
| 18 |
=7
| 5 |
| 18 |
点评:考查了运算定律与简便运算,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简便计算.
练习册系列答案
相关题目
把2.060末尾的零去掉,原数( )
| A、大小不变 | ||
| B、扩大到它的1000倍 | ||
C、缩小到它的
|
甲、乙两桶油,先吃了甲桶油的
,又吃了乙桶油的
,剩下的油相比,( )
| 1 |
| 8 |
| 1 |
| 5 |
| A、甲比乙重 | B、乙比甲重 |
| C、一样重 | D、无法比较 |