An interactive math textbook built backwards.

• finance·log-root-exp

  The Bitcoin Pizza

  On May 22, 2010, a Florida programmer paid 10,000 BTC for two Papa John's pizzas — about $41. Sixteen years later, those coins are worth $1 billion. The most expensive meal in history.

  open →

• module

  The Logarithm

  The trick that turns × into +. The whole module is one equation; everything else is consequence.

  open →

Early. One application live, more in progress. The bar is one question: does this make a curious learner understand something they could not understand before? Yes — it ships. No — it doesn't, however polished.