That's so mean

I wanna lend this to someone right before a maths exam

I'm gonna slowly replace everyone's calculators with these

This and that pen with disappearing ink and I'll be the most hated man in school

"that is the evilest thing i can imagine"- mojo jojo

I need a buy button.

Imagine replacing this with the teachers

Finals.

Dick move of the century

It's a good way to sell defective products