Associative property is a core concept in mathematics that shows a property of some binary operations. In propositional logic, associativity is a valid rule of replacement for expressions in logical proofs. According to associative property law it states that you can add or multiply regardless of how the numbers are grouped. Associative property in simple terms refers to grouping of numbers. It is mainly used to regroup things and any time type of computation depends on things being regrouped.
Associative Property of Addition
a + (b + c) = (a + b) + c
Associative Property of Multiplication
(a $\times$ b) $\times$ c = a $\times$ (b $\times$ c)
Q1) Solve 12 + (15 + 7) Using Associative Property of Addition.
12 + (15 + 7)
= (12 + 15) + 7
= 27 + 7
Q2) Solve 3 $\times$ (2 $\times$ 6) using Associative Property of Addition
3 $\times$ (2 $\times$ 6)
= (3 $\times$ 2) 6
= 6 $\times$ 6