Nothing to do with Spectrums, but a basic, more edgy version of those rubbish Choose Your Own Adventure books your mum got. How 'Go to' worked was, in your Tricolore / History Now! / Whatever textbook, some benevolent genius would have written 'go to page 15' . Then on page 15, they would have written 'go to page 168', and so on, repeating the process, taking you on a thrilling journey through the text book, back and forth, hither and yon, always aware that you could be busted by the teacher at any time for being on the wrong page. At the end of the journey, the connisseur would have lead you to a fine rendering of a spunking cock or simply the words "Gayers flick through books."
The crap 'Go-to' er will merely direct you back to the first page number you started on, making the less obeservant participant go round and round in a circle, although this, to me, was a mark of cuntishness.

Some of the more imaginative pupils used this to great effect in our French textbooks, with a stick man accompanying each instruction. Sometimes he was inserted into the cartoon illustrations in a series of compromising positions.

Maths textbooks were more boring, and therefore the instructions usually culminated in a more prosaic \"Your [sic] gay\" or \"You heart Watters\" (notorious little minger from our year).

The same thing was made in a Biology Book, Supposedly written by the librarian.
The difference was, that suppodedly a girl was inviting you to her house: "Hi, i'm Laura" (go to page x); "I don't have a boyfriend" ; Etc. until it reaches the last phrase: "Then go fuck yourself. The Librarian" (I'm translating from Spanish, so get used).