This is an demonstration of how supermodels can be used to drive a UI in an an MVP fashion. I use a DOM binding library here called superviews.js but feel free to use a view library of your choice.
The demo is an example of the kind of form you need to fill out to obtain a mortgage or loan. Fill out the applicants details, the outgoings like household expenses. Finally any credit commitments need to be filled out. The MAMR (Maximum Monthly Affordable Repayment) is simply the difference between all income less outgoings.