How to flip a coin in your head
by Mark Frauenfelder from on (#48EJS)
I love the book Mindhacker: 60 Tips, Tricks, and Games to Take Your Mind to the Next Level, by Ron and Marty Hale-Evans. One of the tips is how to generate pseudorandom numbers in your head. Say you want to flip a coin, but you don't have one. Just think of a short word, and add up the letter values (a=1, b=2 ... z=26). If the sum is even, it's "heads," if it's odd, it's "tails."
"Bug" is 2 + 21 + 7 = 30. Heads!
The book also shows you how to mentally roll a 6-sided or 10-sided die.