I think it has to do with people wondering why there's numbers with no references yet its a riddle none-the-less, and they tend to think about it for 16 mins before saying w/e and going to find something else to do.
*does an 8 have to do with 8 characters? I guess the -10 could have to do with it costing $10 on the ps3 maybe? the other 8 could be the fact the most materia 1 weapon can hold is 8 maybe, and idk about the +10 maybe you rate it 10/10? idk =/
Also, someone talked about the number 24 though idk where they got that number from all this. There are 24 commands for the enemy skill materia though. random fact?