We are given the following sum

We are asked to create an equivalent addition sentence that illustrates the associative property in addition.
Recall that the associative property of addition is given by

This property states that changing the grouping of numbers yields the same sum.
This means that you can re-group the numbers as you like.
Let us apply this property to re-write the given sum as

Therefore, the above sum shows an equivalent addition sentence that illustrates the associative property in addition.