Here's a geeky tool for Halloween that lets you calculate chances of Humans against Vampires. (There are very few). Recruiting more slayers can help, but not when the Vampire food supplies are walking around shopping at Tesco every weekend. Go crazy!
Omni Calculator 2.0
There are numbers in everything you do. Omni Calculator has 777 easy to use, fast and amazingly fun calculators, so you always get the number you need.