Runge-Kutta methods are popular in the solution of ordinary differential equations. In the notes that follow the solution of the first order equation is solved with the notation
dx/dt=f(t,x)
A worksheet describing the metod is given: Runge-Kutta Methods Worksheet
Spreadsheet demonstrating second order Runge-Kutta: Runge Kutta spreadsheet (Excel)
Spreadsheet demonstrating fourth order Runge-Kutta: Runge Kutta spreadsheet (Excel)