It sounds kinda like you're looking for breadboards. You could build a CPU on one of those, but it's unlikely to do anything interesting and super unlikely to h

It sounds kinda like you're looking for breadboards. You could build a CPU on one of those, but it's unlikely to do anything interesting and super unlikely to hold the attention of a younger audience. The happy medium is probably using both, together. Raspberry Pis and Arduino boards all have documented GPIO you can use to leverage the power/simplicity of a modern CPU with the tactility and practicality of a physical circuit. If you're purely interested in educational value, building a CPU from scratch might not be a good idea for a young audience.