What's the hardest (longest-running) financial calculation?

[rprosperi]

(10-02-2020 08:28 AM)EdS2 Wrote:  I was idly wondering: which of the many functions and features of a financial calculator will take the longest time to run?

Solving for Interest Rate is likely the slowest among the financial features as that is inherently an iterative calculation, however it's possible that some of the statistical functions are similar or even longer. But the 20b/30b have a LOT of functions not typically found in a financial calculator so there could be others as well.