Adding Fractions

Question 1:

7 10 + 2 10
9 10

Question 2:

1 7 + 1 7
2 7

Question 3:

7 9 + 2 9
9 9 = 1

Question 4:

2 3 + 1 4
11 12

Question 5:

3 6 + 1 4
9 12 = 3 4

Question 6:

4 20 + 1 2
14 20 = 7 10