I looked at my pint of beer and thought that it was the smallest pint of beer I ever had. And, then I noticed the marking on the glass said 0.3 L, which is just a little over 10 ounces! I called the waitress over and explained my dilemma . She answered "I don't do math" but went to the bar and poured water from another pint glass into one like mine and saw I was right.
Moral of the story: Don't mess with a math teacher's beer!