Work out the "exponent numerology" of the estimates that come up constantly in
harmonic analysis and PDE — Hölder, Sobolev, Young, fractional integration, the Strichartz
estimates, the restriction/extension conjectures, interpolation, and scaling. Pick an estimate,
fill in what you know, and solve for the unknown. Entries are rational (3/2,
-3, 1/0 for ∞) and may be symbolic (d, 2n+1,
(a+b)/c; use nn for n², and \eps for multi-letter names).
A modern JavaScript port of a 1999 Java applet by Terence Tao
(originally Calculator.java and friends).