Number garden
Small patterns invite a closer look. No answer required. Below are six patterns, each with two worked examples you can check yourself.
The card game to explore these worlds is coming online soon. Until then, you can read every card here with its source.
The only even prime
2 has exactly two positive divisors: 1 and 2.
Every larger even number is divisible by 2, so it is not prime.
A square grows
3 × 3 = 9. A square of three rows has nine places.
4 × 4 − 3 × 3 = 7. Adding one row and column adds seven places.
Triangular numbers
1 + 2 + 3 + 4 = 10. Ten dots can make a four-row triangle.
Two such triangles fit into a 4 × 5 rectangle: 20 dots.
The quiet zero
7 + 0 = 7. Adding zero leaves the number unchanged.
7 × 0 = 0. Seven empty groups still contain nothing.
A growing pattern
1, 1, 2, 3, 5, 8: add the previous two numbers.
The next two are 13 and 21: 5 + 8, then 8 + 13.
Halves meet
½ + ½ = 1. Two halves make a whole.
½ × ½ = ¼. Half of a half is a quarter.