题目内容
判断并改正.
(1)
÷
=
×
=
÷
=
×
=
;
(2)
÷
=
×
=
=1
(3)
÷4=
×
=
÷4=
×
=
÷4=
×
=
.
(1)

×
×
改正:5 |
6 |
3 |
5 |
5 |
6 |
5 |
3 |
25 |
18 |
5 |
6 |
3 |
5 |
5 |
6 |
5 |
3 |
25 |
18 |
(2)
5 |
6 |
3 |
5 |
5 |
6 |
5 |
3 |
25 |
18 |
7 |
18 |
√
√
改正:正确
正确
;(3)
7 |
8 |
7 |
8 |
4 |
1 |
7 |
2 |
×
×
改正:7 |
8 |
7 |
8 |
1 |
4 |
7 |
32 |
7 |
8 |
7 |
8 |
1 |
4 |
7 |
32 |
分析:(1)应把除法改为乘法,再进行计算,因此原题错误;
(2)原题计算正确;
(3)把除法改为乘法时,应乘这个数的倒数,故原题错误.
(2)原题计算正确;
(3)把除法改为乘法时,应乘这个数的倒数,故原题错误.
解答:解:(1)
÷
=
÷
=
(×)
改正
÷
=
×
=
.
(2)
÷
=
×
=
=1
(√)
(3)
÷4=
×
=
(×)
改正:
÷4=
×
=
故答案为:(1)×,
÷
=
×
=
;(2)√;(3)×,
÷4=
×
=
.
5 |
6 |
3 |
5 |
5 |
6 |
3 |
5 |
1 |
2 |
改正
5 |
6 |
3 |
5 |
5 |
6 |
5 |
3 |
25 |
18 |
(2)
5 |
6 |
3 |
5 |
5 |
6 |
5 |
3 |
25 |
18 |
7 |
18 |
(3)
7 |
8 |
7 |
8 |
4 |
1 |
7 |
2 |
改正:
7 |
8 |
7 |
8 |
1 |
4 |
7 |
32 |
故答案为:(1)×,
5 |
6 |
3 |
5 |
5 |
6 |
5 |
3 |
25 |
18 |
7 |
8 |
7 |
8 |
1 |
4 |
7 |
32 |
点评:此题在计算时,应注意:除以一个数(0除外)等于乘这个数的倒数.

练习册系列答案
相关题目