Having keys for ¼, ½ and ¾ would have made sense in Britain when they were using farthings, so that you could express any money amount, e.g. 6¾d for six pence and three farthings. That’s the only context that occurs to me where you need those fractions and no others.
ALT-0169 = © is the one I remember and used to use a lot.
Character Map has been part of Windows for as long as I can remember (i.e. 3.1).
Does the use of the slash character as a fraction bar (as in something like “1/3”) predate computers?
Where? I’m seeing the 1/2 and 1/4 keys but not the 3/4 one.
Edit: Never mind. It’s sharing real estate with the / key.
Recipes. You use these keys A LOT when you type recipes. Which I do at least once or twice a week. I miss those keys from my typewriters!
I have an HP 32SI RPN calculator that can do just that and as easily as entering all decimals. Those HP’s are wonderful machines