Your confusion comes from the fact that dividing a quarter in half is 0.25/2. That's not what's shown in the comic. Dividing by 0.5 is the same as multiplying by 2. It's just a quirk of syntax, the way we write math. If you spelled it out using English the comic would say "multiplying a quarter by two equals a half". The confusion just stems from someone's unfamiliarity with mathematical notation.