Adding common denominators
1/4 + 2/4
3/4
4/5-1/5
3/5
45+45
90
15-10
5
9X5
45
3/5+1/5
4/5
9/10-2/10
7/10
123+234
357
29-10
19
6X6
36
9/12+1/12
10/12
23/25-3/25
20/25
256+156
412
175-100
75
10X4
40
6/10+1/10
7/10
18/28-10/28
8/28
897+24
921
193-187
6
4X6
24
25/29+1/29
26/29
95/100-90/100
5/100
765+873
1,638
999-876
123
3X7
21