This playground is running off CodeIgniter and has been setup to demo/prove some concepts with regards the framework.
At the same time though, i thought it would be useful to start putting together an area where the basics of compound interest and it's applications can provide some value. As a result, we have the first installament:
Calculators for compound interest, amortization and doubling (halving) time for the value of money.
When you read you begin with A,B,C. Right? So here, we start, not quite at the very beginning... but close enough.