Find the union of the following number sets: Set A = {1, 2, 3, 4} and Set B = {3, 4, 5, 6}.

Step 1 ：To find the union of two sets, we combine all the elements of both sets. Duplicates are only counted once.

Step 2 ：Set A has the elements {1, 2, 3, 4}.

Step 3 ：Set B has the elements {3, 4, 5, 6}.

Step 4 ：Combining all the elements from both sets and removing duplicates, we get {1, 2, 3, 4, 5, 6}.