If you ever visit Berlin, especially with kids, the city has a lovely Technology Museum with an computer section that also features Zuse replicas and gear, including a replica of the still-mechanical Z1. I think Zuse himself made and donated it to the museum.

https://en.m.wikipedia.org/wiki/Z1_(computer)#/media/File%3A...

I absolutely love the giant honking hand-crank you can manually turn to make it go.

As a child seeing the mechanical Z1 really drove home for me that computers are understandable and not magic, literally breaking what they do down into little managable parts and steps and the art of making a computer is in sizing (how many adders do you need?) and arrangement (how can you make it produce results faster?).

With some erudite commentary and informed pointing-at-things I think you have a good chance to recreate that revelation for your kids too.

More info on the Z1: https://www.mi.fu-berlin.de/inf/groups/ag-ki/publications/Z1...

It's quite magnificent how close this still is to modern CPU architectures, the major innovation of branch prediction aside.