*gathers all of the people in the world who write the number 7 with a little dash in the center of it so I can study them like little critters and find out what makes them do that*
There’s actually a lot of history regarding the development writing systems and why there are different visual representations of numerals, but the short answer is: it’s regional, and you probably picked up how to make your numbers look based on your parents or your primary school teachers
I do it out of spite because in grade school a kids detective story identified the culprit by saying NO American wrote their sevens with a line and I thought that was super flimsy evidence and it made me so mad I started putting a line through my sevens so the fictional detective would be wrong and then kept doing it for several decades since.
I do feel one can’t underestimate the “elementary school child taught themselves how to do this Out Of Spite” crowd
























