Adding Fractions

Question 1:

2 9 + 7 9
9 9 = 1

Question 2:

1 3 + 2 3
3 3 = 1

Question 3:

1 10 + 3 10
4 10 = 2 5

Question 4:

4 5 + 1 8
37 40

Question 5:

1 3 + 3 15
8 15

Question 6:

1 15 + 1 5
4 15