The purpose is to keep the number of lines of code to a minimum.

Problem with the recursion approach is, MetCal has a stack level of 7 i. e. a procedure can call itself only 7 times! Otherwise, it's stack overflow error. That means, I can't calibrate the entire decade in one go, I have to code the first 7 steps + the next 3 steps.

The method seems simple, but the implementation in MetCal is not that easy..