rub (something) out
Definition: to erase something written in pencil, chalk or special ink, using a rubber (British English) or eraser (American English).

E.g.1: She quickly rubbed out what she had written so that the teacher wouldn’t see it.
E.g.2: That’s not right! Rub it out and start again!

This phrasal verb can be separated. (E.g.2)