How much money should I donate to charity until it's okay for me to shoot up a school?

"As of 2011, the Environmental Protection Agency set the value of a human life at $9.1 million. Meanwhile, the Food and Drug Administration put it at $7.9 million — and the Department of Transportation figure was around $6 million."

Lets say it is 8 million USD per child. 8*500= 4 billion dollars.

tl;dr a lot.

You're confusing "school" with "church". Don't donate, detonate!

Depends on the school, if it's a Detroit public school then just drop a dollar in the cup on the way out like everyone else does.

You come to me first. I'll make sure your guns working properly before you head out.