What is the method for calculating the union of two sets A and B?

The method for calculating the union of two sets A and B involves combining all elements from both sets while ensuring that any duplicates are eliminated. The union is essentially a new set that includes every distinct element that is present in either set A, set B, or both.

When performing this operation, you start with all the elements in set A, then add the elements of set B. If there are any elements that appear in both sets, they will only appear once in the resulting union set. This property of the union operation is fundamental in set theory, as it emphasizes the importance of distinctness in combining elements from different sets.

In contrast, simply adding the number of elements in both sets would not account for duplicates and would lead to an incorrect representation of the size of the union. Taking the intersection, which focuses on elements common to both sets, and listing elements from only one set, do not reflect the nature of the union operation at all.