1. You still feel terrible about 9/11
2. You don't like math
3. You don't have a calculator
4. Are emo and don't want to laugh (assuming the first three don't apply)
I can make 9/11 spell hahahahahahaha. First of all, what's nine divided by eleven? .818181818181 right? Now we since "A" is the first letter of the alphabet and "H" is the eighth letter just plug them in. It's .HAHAHAHAHAHAHAHAHAHAHAHAHAHA infinitely so 9/11 = .HAHAHAHA.
There you have it my proof. I hope you enjoyed it.