Frobenius theorem (real division algebras)
= Frobenius theorem
{disambiguate=real division algebras}
{c}
{tag=Classification (mathematics)}
{wiki}
= Classification of associative real division algebras
{synonym}
{title2}
There are 3: <real numbers>, <complex numbers> and <quaternions>.
Notably, the <octonions> are not <associative>.