Write the answers to the addition questions below (the first one is done for you).
1 + 3 = 4
1 + 7 = 8
1 + 5 = 6
3 + 6 = 9
4 + 1 = 5
5 + 3 = 8
8 + 1 = 9
6 + 1 = 7
2 + 5 = 7
2 + 3 = 5
1 + 6 = 7
3 + 4 = 7
5 + 1 = 6
3 + 5 = 8
4 + 5 = 9
1 + 1 = 2
5 + 4 = 9
1 + 4 = 5
4 + 3 = 7
1 + 0 = 1