Another simple math topic I thought of today, how betting a draw is better than check/calling a draw (again assuming it's all-in for simlicity) because of the extra equity gained by them folding some percentage of the time which could be accompanied by garphs and such.

Expanding on what dozer said, you could represent what dozer said about all-in preflop equity and show how it can be modeled by brownian motion (with bias) and show that some percentage of the time a bad player will show a better short term win rate vs a good player because of the variance.