Which programs do you actually use in your calculator?

[Dave Britten]

Hmm, let's see...

Binomial distribution and negative binomial distribution get used frequently on many of my calculators. Ditto for prime factors (adapted from this old HP-67 Math Pac 2 program).

My 27S has a bunch of solver equations in it. Unit conversions, tapered IV rate calculation (trapezoid area, basically), drip-rate for gravity IV infusion, TVM with an introductory interest rate period, balls & urns (or "stars & bars") probability...

The 48G that I use solely as an alarm clock (due to a problem with the display annunciators) has a couple of programs for quickly setting an alarm for the next occurrence of 6:30 AM, or the next occurrence of the time specified on stack level 1.

My DM42 has a program for tabulating daily fluid I/O.

Also, I'm a heathen, and have a TI-84 Plus CE that I use often. I have an ETA program I use to estimate completion time of a process with a known current degree of completion and final value. It lets you select from several different curve fits, in case of a process that doesn't progress linearly. Comes in handy when I want to know what time I can expect SQL Server to finish restoring a ~1 TB backup. I've also adapted most of the algorithms in William M. Kolb's "Curve Fitting For Programmable Calculators" to the 84.