That's right, a TI-30Xa scientific calculator. The little workhorse of a calculator. I actually found one of these at Fremont High a few years ago and it's been my backup calculator for when I can't find my TI-84+ Silver.
I found this one in the E-waste bin in Segundo when I was recycling a bunch of batteries that I've drained with my Joule Thief. It was sitting there, begging me to save it. It was DOA, but the exterior looked alright; no cracks, no water damage. I grabbed my mini screw driver set and opened both calculators. The 30Xa is a wonderful design. 6 little screws, and the back came right off. No glue, no scary plastic clips that you think are there.
Swapped the batteries in the two calculators, and the new one fired right up. Now I just got to go buy another pair of GPA76 button batteries and I'll have another scientific calculator sitting around. I love E-waste bin diving.
The inside of the calculators really surprised me. The PCB layouts of the two calculators was completely different. They even had different trace thicknesses and it looked like one of them had more layers. The CPU on the new one also lacked the foil shielding the other one had and only had the black epoxy that is the bane of every hacker.