# Associativity
Is a property of binary operations that is satisfied if, for every three elements of $a$, the following holds:
$
(a_1 \circ a_2) \circ a_3 = a_1 \circ (a_2 \circ a_3)
$
Multiplication and subtraction are both examples of associative binary operations on numbers. Division and subtraction, however, are not associative.