Good tiny device for storing/summing up a few lists of numbers throughout the day?

[Dave Britten]

For medical reasons, I have to track fluid intake and output in various forms and categories throughout the day. Then I enter the daily totals into a spreadsheet with some other health info. That's probably enough detail to set the scene without offending anybody.

I've been tracking the numbers in Lotus 1-2-3 on my 200LX with the aid of a couple simple macros, but it seems like a bit of overkill, and I'm exposing a relatively expensive and delicate device to a lot of wear and tear (both from use, and being carted around in my medical supplies bag). A 95LX might be a less valuable option - I have two I could use - but would be just as bulky. The 17BII is also a good candidate with its sum lists, but it can be a bit keystroke-heavy getting numbers into several different lists, and then getting the total for each list at the end of the day. I do like the alarm feature though, as I can set it to remind me to rotate the data at the end of each 24-hour reporting period.

I'd whip up some 48GX/SX programs to do the entry and analysis, but it would still be fairly bulky, especially since I'd need the soft case to protect it inside the medical bag. And the GX would be just as expensive to replace as the 200LX, if not more so. Printing records on my 82240 would be neat, though.

Anybody have any thoughts on something durable, not super pricey, and perhaps pocketable? Essentially, I need to be able to maintain multiple lists of numbers over a 24 hour period, and quickly see the total for each of those lists. Then wipe them (or store an archive copy) and start over after I've recorded the totals elsewhere.

EDIT: Forgot to mention that I need to record the amounts in mL, so having a means of converting from fl oz without too much trouble would be a big plus. Even if it's just the ability to multiply an entry by some stored conversion constant, which is what I can do with the 17BII.