Calculator

Just an answer.

Type an expression, get a result. Name a value to reuse it later.

A structure is the algebraic system expressions are evaluated in. Real numbers is ordinary arithmetic. The Z/nZ options are finite modular arithmetic: every result wraps into {0, ..., n-1}; with prime n (2, 5, 7, 11 here) every nonzero element has a reciprocal, so division works for anything except 0.

Store a value in a variable with =, or directionally with ->/<-: k = 3*r, 3*r -> k, and k <- 3*r all store the same value in k.

Type an expression below, or "name = expr" (or "expr -> name" / "name <- expr") to save a value.