The fertility formula, to predict the population the following year:
A fake number (called “Wau”) to imagine infinity (via Numberphile):
Drawing a square root of 5 (via James Grime):
Pebbling a Chessboard (via Numberphile):
Kolakoski Sequence:
Proof for probabilities in a Wythoff’s game
Probability that everyone will be eliminated simultaneously in Simon’s “Hat Game” (a card game he invented):
Finite List of Primes:
Creating consecutive numbers by using various operators to connect four fours:
Geeks out of the box 