A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Ed Popko
Date: 2019 May 6, 02:42 -0700
In high school math class, we were encouraged to use a kid's "Magic Slate" to work homework problems. This was not the brand available then but it is the same thing marketed today. When we were satisfied with the results - a proof, an application of an equation etc. - we would then copy it only regular notebook paper in ink. Essentially they were a black wax-like base and a plastic cover sheet. When you wrote on the plastic, the under wax imprented the image on the plastic. To erase, you simply lifted the plastic cover sheet and started anew.
Not exactly slate and chalk but the modern version I guess.