I'm Not As Bad As I Thought

I guess I'm not as bad in math as I thought. I showed yesterday's TWIT picture to quite a few friends at work and at school, and out of the dozen people that saw it, only one noticed the mathematical error. I will give props to the 'Rents. As soon as they saw the picture, they noticed the subtraction error right away. I guess that goes with all of their years of checking over my math homework in school.