addition
ad-di-tion
noun
The arithmetic operation of combining numbers to find their sum.
"Basic addition is taught early in primary school."
noun
An item, person, or part that has been joined or included.
"The new intern is a welcome addition to the team."
noun
The action or process of joining something to another.
"The addition of new features improved the software."
Thesaurus
Synonyms: accession, summation, gain, increase, improver, add-on
Antonyms: deduction, subtraction