# table of addition up to 12

Because of the commutative property of addition, it does not matter if the row or the column gives the first operand.

 + 1 2 3 4 5 6 7 8 9 10 11 1 2 3 4 5 6 7 8 9 10 11 12 2 3 4 5 6 7 8 9 10 11 12 13 3 4 5 6 7 8 9 10 11 12 13 14 4 5 6 7 8 9 10 11 12 13 14 15 5 6 7 8 9 10 11 12 13 14 15 16 6 7 8 9 10 11 12 13 14 15 16 17 7 8 9 10 11 12 13 14 15 16 17 18 8 9 10 11 12 13 14 15 16 17 18 19 9 10 11 12 13 14 15 16 17 18 19 20 10 11 12 13 14 15 16 17 18 19 20 21 11 12 13 14 15 16 17 18 19 20 21 22 12 13 14 15 16 17 18 19 20 21 22 23 13 14 15 16 17 18 19 20 21 22 23 24

It is obvious that the longest northwest to southeast diagonal contains numbers of the form $2n$.

Title table of addition up to 12 TableOfAdditionUpTo12 2013-03-22 16:36:05 2013-03-22 16:36:05 PrimeFan (13766) PrimeFan (13766) 5 PrimeFan (13766) Data Structure msc 11B25 msc 00A05 msc 00A06