But this is not 1981. Which UK home that contains a person stimulated by maths, technology or computers science does not also already have a PC or and Android device?
Right, but in 1981, I presume that in order to get the computer to do anything fun, you had to learn how to program it. Today's computers and phones are basically complete as far as anything a kid would want to do with them. Even in the mid-1990s when I got my first computer, it would have become an "AOL box" if I hadn't had a family friend who was a programmer. Sure, by high school they might have some ideas that might require going a little deeper than ready-made software, but microcontrollers do from the get-go.