7 Answers. “Subtract” is the word. Though the obsolete word “substract” did exist, any occurrence you see these days is most likely just a common mistake, formed by analogy either with “abstract” or with other languages whose corresponding words do have two ‘s’s.
What is the meaning of subtracted?
transitive verb. : to take away by or as if by deducting subtract 5 from 9 subtract funds from the project. intransitive verb. : to perform a subtraction.
