I was about seven (it was 1971) at the time that I discovered "Tutortext: Basic Mathematics" in the village library. It was a volume from an American series of popular education materials aimed at those who "wish to learn ... and yet have to teach themselves". The educational method was devised by Norman Crowder, from the Educational Science division of US Industries Incorporated - an outfit that in retrospect sounds like a front for James Bond!
And well it might have been, because its unusual style seemed just as futuristic as one of Q's gadgets. Each chapter started with a page of explanation and a question with multiple choice answers leading to other pages; some of them explained where you had gone wrong, and one of them congratulated you on your progress and took you on to the next step. It all seems rather pedestrian now with our history of computer-assisted learning and personalised and adaptive hypermedia, but to me at the time it was just magic. It forced me to engage with the problems and consider my solutions and to seek the praise that the text meted out!
I have just managed to track down a copy of the book (from an Amazon reseller!) and it has provided me with a tremendous dose of nostalgia. Still, I might just give this book (copyright dating from the year before I was born) to my youngest daughter to see if it helps her.