I'm looking for a word or phrase to describe when someone copies something down incorrectly.
Specifically, the situation I am thinking about is when someone is solving a problem (using pencil and paper), and in one step, they incorrectly copy an equation or expression from their previous step:
Joe Smith got 1 point off on his math homework for a ____ [error] when he accidentally changed a 7 to a 1.
I originally arrived at the phrase "typographical error", however when I looked this up it seemed to only apply in the case of printing or typing (as in using a keyboard or typewriter), and does not seem to apply when writing with pencil, nor does it quite convey an issue with copying from a previous step.
Is there a more appropriate phrase that I can use?
EDIT: I'm specifically looking for a noun (or noun phrase) that can be used in the same way that "typographical error" is used.