I originally learned with an old Radio Shack electronics kit like this one:

https://old.reddit.com/r/electronics/comments/g6vyjc/old_ele...

I tried to get my kids interested with the modern equivalent, Snap Circuits, but they didn't take to it. It was too limited and toy-like.

I later acquired an old electronics kit like the above, and they were much more interested in that. You can still find the older kits on eBay for not too much money.

Keep in mind they may not take to it like you did. My kids' own interests went to more mechanical stuff and small gasoline engines and electric motors instead.

Don't steer their interests, feed them. Provide breadcrumbs for their curiosities.

I used Arduino sets to teach kids electronics and minimal programming. We created various simple devices with sensors and motors using resistors, capacitors and transistors to construct interfaces between digital inputs/outputs and analog devices. This way kids understand why we need analog components in digital circuits. The simplest possible example is R + LED to limit the current. You can explain that R is a thin tube which limits amount of electrons flowing to the LED. Then you can demo the R-divider to cut the voltage on the digital input. Then add a capacitor and demo kids the slowly flashing LED driven by digital output. Use oscilloscope to visualize the signal - it's hard to understand how capacitor works. Then use transistors and MOSFETs to drive motors. I also created a 3D printed parts to assemble working models like the radar, barrier and real clock driven by the stepper motor.

Why analog out of interest?

Digital might be a better place to start these days with all of the cheap components you can buy and some of the fun things you can build with digital electronics? Not my kid, but I brought a kid in my family a pack of cheap components and we built things together based on his interest and creativity.

I'd probably just buy a pack of components and build stuff with them like a lego set. Anything you build will present an opportunity to talk concepts like voltage, current, etc. I guess if they're nine you might be able to cover some of the basic math too.

For a child, this is still a routine, but if the school lessons are boring, such an unusual lesson can even be interesting. Then you need to measure the wires, carefully lay out all the parts and wires on the table, and be careful not to mix up the positive and negative terminals. I don't let them use a soldering iron, but they can, for example, press the power button while I take measurements. Sometimes you can take measurements yourself. Listen to why something didn't work. In any case, analog electronics is for those children who value attentiveness, especially if they need to build a truly useful device and are missing parts.

I don't have any kids but if I ever do, I'd get them one of those spring and wire based 30 In 1/etc kits. That's how I fell in love with electronics.

Building a simple AM radio might be an interesting project.

There might be a more kid-friendly/kit version of something like this:

https://m.youtube.com/watch?v=_AI2Jixj5Bs

My daughter had one of this https://elenco.com/snapcircuits/

haven’t done it, but I’d try a rain sensor. and if the child is into music, a guitar tone knob.

i taught digital first, kids get logic gates fast, but analog (why singals aren't clean 0/1) clicked way later for me