This video shows the organ function grinder from the National Museum of Mathematics as it solves a quadratic function for a specific input. This video focuses on converting an input into an output and challenges you to calculate the value for a given input before the function machine does.

The function used in the video as an example is:

double, square root, +3    OR   

I wish they had used not used square root in an introduction to functions, but its inclusion does pose an interesting question: For which inputs do you get a whole number output?