The methods activity allows you to plot numerical approximations to the solution of an ordinary differential equation y'=f(t,y).  The methods employed in this activity are Euler's Method as well as Second and Fourth Order Runge-Kutta.  The activity includes a table of the approximations that correspond to each method.  You can easily toggle between the different methods as well as resize the window using pinch and pull gestures.  Enter your own equation or explore one of the preloaded equations.