Your job: build a spinner where landing on brass has probability 3/8. Slide to set how many of the 8 sectors are brass.
2/8
You've set P(brass) = 2 ÷ 8 = 1/4
Probability is everywhere — weather %, raffles, board games. And it runs both ways: given the chance, you can work out how many favourable outcomes you need, or design something to hit a target.