Number Systems

Start counting: 1, 2, 3…. That's the naturals, and they're enough — until you owe someone sheep and need numbers below zero. Add negatives and you have the integers — enough, until you split a pizza and need fractions. Add those and you have the rationals — enough, until a square's diagonal demands √2, which fits in no fraction at all. Each system was born from a question the previous one couldn't answer.