I never knew that this actually had a name but certainly did partake of it when I was in elementary school at the time that affordable digital calculators began to appear on the scene. Beghilos is the term for creating ‘words’ using a digital calculator.
Kids have been playing with the word-creating possibilities of calculators since they started to appear in the 1970s. It didn’t take long to discover that 0.7734 upside down made hEllO. One of the earliest attested examples from this period is 5318008, which when turned over spells boobies. If your display is big enough, you can enter 53177187714, which makes hillbillies; mine has only ten digits so I get illbillies (sick goats?) and the longest word I can make is 378193771 (appropriately, illegible).
And, in my case, there is no denying the conclusion of the post:
To be 37819173 to play this game in the 1970s, you had to be young, geekish and slightly bored.