0
Anonymous
It is: 1318 plus 19 = 1337
18 and 19
17, 18, and 19
18, 19, 20
37 - at least it was when I went to school !
54
They are: -18+(-19) = -37
41 - 9 = 32
17+18+19
18 + 19 + 20 = 57
18+19 = 37