Think it was my soph year at ISU when the bookstore blew out their remaining stock of slide rules; I picked up a very fine one for pennies on the dollar, just for nostalgia. I’ll need to dig it out tonight.
In Jr High I also had a 3” x 5” circular slide rule, which avoided the answer going off the end, but just circled around and you could read it instantly; it also had a slide-out card with the Periodic Table and all kinds of constants, equations, etc; I used that thing for years, even after I got a sci calculator.