1 + 9 = 101 + 9 = 10
2 + 9 = 112 + 9 = 11
3 + 9 = 123 + 9 = 12
4 + 9 = 134 + 9 = 13
5 + 9 = 145 + 9 = 14
6 + 9 = 156 + 9 = 15
7 + 9 = 167 + 9 = 16
8 + 9 = 178 + 9 = 17
9 + 9 = 189 + 9 = 18
10 + 9 = 1910 + 9 = 19