The sign for "mistake" also means "wrong" and it has a couple of variations.
MISTAKE / inaccurate / "be wrong" / "an error"
The sign for MISTAKE has a variation that can mean "make a mistake," "make an
error," or "have an accident." The movement twists a
"Y-hand" across the chin. This version is often used as a type of
conjunction connecting parts of a story.
MISTAKE / "make a mistake" / "have an accident" / "whoops"
How many errors did you get on the last (previous) test you took in this
= PAST TEST THIS CLASS YOU WRONG how-MANY?