I keep a couple of cheap 4-banger (+,-,*,÷) calculators around and I recently found one of them gave funny results and had bad display segments.
You know, $4,xxx,xxx.28 in the checking account instead of the approximately $8,xxx,xxx.28 I was expecting.
This one had a tip-uppable display, so no wonder some data lines went soft.
I decided that forevermore when I pick up a calculator, I was going to load the display with eights to verify all the segments were working.
Another time a friend of mine brought back a bunch of solar calculators from Thailand, where his wife was born, and gave them out to everybody as little gifts.
Worked fine until the battery got low, so I stuck it under a lamp to recharge it. No amount of recharging worked, so I figured it was door-nail dead, and took it apart, thinking I'd rescue the photocell for various silly experiments. You know, just for grins. Hook it up to a meter and see what kind of voltage it developed. Grins. Come on, you know what I mean.
But I found the photocell had no wires going to it and further inspection revealed that this "photocell" was merely a piece of cardboard printed up to look like a photocell with 4 segments.
I hope he didn't pay too much as import duty on them.
Terry, 230RN