Removed erroneous statement about matrices.
With more than three numbers, there can be many ways to do the addition. For example, with 4 numbers one of the ways is <math>2 + 3 + 4 + 5 = ((2 + 3) + 4 )+ 5 = (5 + 4 )+ 5 = 9+ 5 = 14</math>.
The [[associative property]] of addition is different from the [[commutative property]]
. For example, addition of matrices has the associative property but is not commutative. If <math>A</math>, <math>B</math>, and <math>C</math> are three matrices, then <math>A+(B + C)=(A+ B) + C </math> but <math>A+ B \neq B + A </math>.