Convert 1-3999 both ways, see how each numeral adds up and catch non-standard forms like IIII.
Test any number for primality with Miller-Rabin, then get its prime factorisation and every divisor.
Mean, median, mode, quartiles, range and standard deviation for any list of numbers.
Add tax to a net amount or strip it back out of a gross amount, with common rates one click away.
Size a rain tank from a monthly mass balance of catchment, rainfall, runoff coefficient and household demand, with days of autonomy.
Mass to moles to STP volume for any compound, plus M, mM, mol/L, g/L, mg/mL and ppm, with the molar mass table shown.
Acoustic Doppler for a moving source and observer, and the relativistic longitudinal factor for light, kept strictly apart.
Wien's peak wavelength and the Stefan-Boltzmann flux, with the luminosity of a star at the radius you type.
