The prime factors of the integers visualised as sets of recursively nested circles. Entirely algorithmic, with zero arbitrary positioning or fudges. Many insights to be gleaned!
Show and explain to your math learners – prime numbers and composite-factors are universal math, not dependent on our ten-fingers-based number system.
Imagined and created by Toby Kurk.
Code revised and improved with the help of
Claude ai.
v1.0c136 (2026‑Oct‑27)
Shown a random number between Min and Max. Min is your lowest number not yet known or easy; Max starts at 20 and widens as you answer correctly.
Numbers you miss or reveal come back soon. A correct answer pushes a number further out, and each repeat correct answer pushes it out further still.
Answer “Prime” or type its factors, e.g. “2, 2, 13” or “2^2 13” – “p”/“prime” also count as Prime.
Initial range
Prime, or its prime factors?
A large base makes the cells too small to tap easily on this screen.