ANSWER
Simplify the answer, if needed.
Step-by-step explanation
We want to identify the last thing to do after adding fractions.
To write fractions properly and neatly, they have to be written in their lowest terms. This means that after any operation is carried out with fractions, they must be simplified and reduced to their lowest terms.
Hence, the very last thing to do after adding fractions is to simplify the answer, if needed.