(14 + 6) + 11 is equal to 14 + (6 + 11). The associative property of addition was used, which is when the equation is the same no matter how it is grouped.
(14 + 6) = 20, and 20 + 11 = 31.
(6 + 11) = 17, and 14 + 17 = 31.
They were grouped differently, but they had the same sum.
