A number nazi, or numerical nazi or mathematical nazi.They are as annoying and similar to a grammar nazi. but instead of words they reign over numbers and, math.
Jeff-Hey Mark, what is 1 + 1?
Mark-Bitch its WINDOW!
Jeff-No dip shit, it's 2!
Number Nazi-You both are dumb-asses, 1 + 1 is an expresion, therefore, there is no equal sing.
Grammar Nazi-You spelt "expression" wrong.