On offer is an older graphing calculator. I used this at college, but can't remember how to use most of it, so if your maths is better than mine, you might like it. It comes with the plastic protective slide cover and 4 batteries, so it's ready to go.

I've done some basic calculations on it and it works and the screen is fine. I don't have the manual any more, but it's on the web in various places including here:

https://www.manualslib.com/manual/372816/Texas-Instruments-Ti-85.html

Collection from Deal

Graphing Calculator Texas Instruments TI-85 (CT14)