1) 5 + 3 = Comprobar
2) 12 - 7 = Comprobar
3) 20 + 15 = Comprobar
4) 10 - 4 = Comprobar
5) 7 + 6 = Comprobar
6) 15 - 5 = Comprobar
7) 8 + 9 = Comprobar
8) 18 - 9 = Comprobar
9) 4 + 11 = Comprobar
10) 14 - 3 = Comprobar
11) 9 + 5 = Comprobar
12) 13 - 6 = Comprobar
13) 6 + 7 = Comprobar
14) 16 - 8 = Comprobar
15) 3 + 2 = Comprobar