How do you use your calculator(s)? (or did*)

[brickviking]

I've already approached the "what do I do with my HP calculator..." in the other thread, so I'll approach the "did" portion of this question (and the non-HP calculators), as I've had a HP-34C in the past and still have the fx-9750G+ and the GII.

In the past, I mainly used calculators in the supermarket to add up totals; here's an extract from a blog article I wrote back in 2008 about the fx-9750G+, fx-82MS and others:

(09-15-2008 10:00 AM)brickviking Wrote:I was using the FX-82MS to motor around the supermarket, adding up what we'd bought, in about seven different categories. I came across a nice way of doing this, (with keys in []):

[ALPHA] A + ([ALPHA] X × 1.175) [SHIFT] [STO] A which looks like this, once it's in the top line of the 82MS: A+(X×1.175)->A

Basically, that takes whatever's in register A, adds (X multiplied by 1.175) to it, and sticks the result back into register A. A variant on this removes the multiplication, and simply acts as an addition, storing the result back into the register:
[ALPHA] A + 2.25 [SHIFT][STO] A which, again, looks like this: A+2.25->A

I simply used the six letter registers for different categories of goods, used the X and Y registers for price-per-kilo costs, and combined with the previous formulae, substituting register letter as I went. Once I'd finished I could get a grand total simply by adding together the entries in the six registers, thus: A+B+C+D+E+F=

…
This calculator (the HP-34C) had the ability to store a key sequence, and also had multiple registers I could stuff numbers into and retrieve from, in addition to a prompt for number, so it had nearly everything I needed, except for reliability. The calculator was getting long in the tooth when I got it, and it was showing it - with occasional times where I couldn't see the display, the Run/Stop switch wouldn't always make the calculator change modes, and the battery hatch was falling off. In the end, the calculator was retired into the bin, though I wish now I'd kept it.

The program I generated for the HP-34C was previously generated from that sequence of instructions I'd used for the 82MS:

1. Prompt for a value
2. Read value from the user
3. Add that value to a running summation
4. Go back to step 1
   

I think I may have made a modification on this that took two vars off the stack, multiplied them together and added them to the running total but I no longer have the 34C, nor the programs I wrote.

Because of the programmability of the 9750G+, I was able to seriously expand the "program" I'd used on both the 34C and the 82MS, to the extent where I was able to actually release my program as a fully working program to casiopeia.net. I've since bought a 9750GII with USB connectivity, which allowed me to upgrade the program further and add features far faster than with the original G+. These days, the GII is now my fortnightly grocery "driver" as it's definitely faster at running my "little" program. As I said in the other thread, my HP-50G gets used for aircraft stuff, grocery total holding and unit conversions.

(Post 146)