Thinking of when I was 12 (2005?), microscopes and magnifying glasses helped me understand. Depends on device DPI (cell phones have an insane number of pixels per inch; desktop screens are usually less dense).
If you can zoom in enough to see subpixel elements, and pull up a color wheel, it's very intuitive to see that the screen is made of pixels, and the pixels are made of three elements.
I don't know about books, though. I remember reading the binary/computers chapter of How Things Work and being thoroughly confused at that age. There was some extended allegory about white mammoths and black mammoths.
Did you have The Way Things Work or The New Way Things Work? I had the latter around the same time. I thought the extended computer section (Bill's Gates!) was very helpful. I still really like the visual in which the image of a mammoth is turned into a series of pumpkin/no pumpkin signals being launched through the air, then becomes a picture of a mammoth on the other side of the field. I think it got a bit too technical for me when it started showing how transistors are constructed-- I guess I should've stuck with the pumpkins.
Now I have both editions and have looked through them side-by-side. It's a bit unfortunate that some pages were dropped to make room for the expanded digital section in the newer edition, but well worth the trade-off for more/better explanations in the digital realm.
Just took a look over my bookshelf, but they haven't made it with me through moves.
I do still have Incredible Cross-Sections. That was another of my favorites to flip through. It looks like there are reprints and new versions. Would definitely recommend for kids.
If you can zoom in enough to see subpixel elements, and pull up a color wheel, it's very intuitive to see that the screen is made of pixels, and the pixels are made of three elements.
https://en.wikipedia.org/wiki/RGB_color_model#/media/File:Ad...
The Pico-8 might be a approachable way to explore retrocomputing. It's an in-browser console modelled after GameBoy-era consoles.
https://news.ycombinator.com/item?id=18240375
I don't know about books, though. I remember reading the binary/computers chapter of How Things Work and being thoroughly confused at that age. There was some extended allegory about white mammoths and black mammoths.