The objective of this document is to provide an oportunity to explore different basic numerical algorithms interactively. Topics covered include precision of computation, vector calculus in 2D and 3D, systems of linear equations, some numerical constants, evaluation of user specified functions and of the elementary functions with their inverse functions (exponential, logarithm, trigonometric and hyperbolic), approximation of zeroes and of integrals, and numerical solutions of first order ordinary differential equations.