1) Be daydreaming when the math teacher asks you what would you subtract from tbe equation

2) Say you'd subtract yourself from this class

3) Walk out.

Okay, this one wasn't me, but it happened in my math class, and it was spectacular.

Step 1: Make sure you are in or around a group of girls

Step 2: Say any variation of the phrase "Teenage girls are among the dumbest people alive"

Step 3: Guard your groin and laugh maniacally