口算习题-约分练习
江苏科技大学研究生院-品牌顾问
约分练习
姓名
(1)
当分数的分子和分母个位上是0.2.4.6.8 .时 。不是最简分
数，一定有公因数2。
(2) 当分数的分子和分母个位是0或5时，不是最简分数，一定有
公因数5。
（3）当分数的分子和分母各个数位上的和能被3整除时，不是最
简分数，一定有公因数3
。（4）当分子和分母不是以上情况时，那么就看一下，是否有公因
数7，11.
13，17.19。
24643528
36
=
80
=
49
=
70
=
26511654
91
=
68
=
40
=
81
=
12163230
=
= =
36804836
=
20253918
56
=
60
=
78
=
45
=
15752428
= = =
36906448
=
32364042
36
=
80
=
72
=
70
=
46485051
= = =
82847585
=
10121416
36
=
60
=
49
=
64
=
12121216
= = =
48567248
=
20202530
36
=
75
=
80
=
75
=
30152532
= = =
48757548
=
36343542
64
=
51
=
75
=
70
=
46
69
=
48
80
=
64
64
72
=
80
=
30
48
=
15
75
=
15
=
75
3690
=
36
34
64
=
51
=
46
69
=
48
80
=
12
=
16
3680
=
20
56
=
25
60
=
24
=
64
36
80
=
32
36
=
36
80
=
26
51
91
=
68
=
46
82
=
48
84
=
50
75
=
72
81
=
25
75
=
24
64
=
35
75
=
50
75
=
32
48
=
39
78
=
35
49
=
40
72
=
16
40
=
50
75
=
54
90
=
120
144
=
32
48
=
28
=
108
48
144
=
42
=
12
7056
=
54
90
=
12
72
=
30
=
16
3664
=
18
45
=
50
75
=
28
=
18
7081
=
4252
70
=
90
=
54
75
81
=
95
=
51
85
=
52
90
=
1012141618
36
=
60
=
49
=
64
=
81
=
1212121618
= = =
=
4856724890
=
2020253028
36
=
75
=
80
=
75
=
91
=
64
72
=
64
80
=
72
81
=
108
144
=
96
120
=