ASL sign for: minus

With the subtraction of; (before a number or of temperature) below zero; after a grade (e.g. B-); a disadvantage.

Related signs: SUBTRACT.

Gloss: GLOSS: twelve minus eight equal how-many?.

English equivalent: It is equivalent to 12 - 8 = how-many?.

This one omits the signed word EQUAL-to especially when repeating the mathematical equations in a session.

Hmm, no words found now but, hey, it doesn't mean there is no expression for this concept in ASL.