As many as you like and not just from the Roman alphabet.
However, it would be sensible to avoid letters that are similar, in shape, to numbers to avoid confusion. Forexample, O and 0. Or l and 1, or 2 and Z, or 5 and S.
Some symbols used to represent letters in music notation are .
Yes, English and Greek characters (letters) are the most frequently used symbols for variables.
OUIJA
there are lots of chemical symbols about 110 but they are only used for elements not compounds.
Variables (letters like x and y)
No. The Romans used letters to represent quantities. Whereas the Greeks used letters and symbols to represent quantities.
The symbols used in Gaelic numbers are a combination of letters from the Latin alphabet and some unique characters, such as the dot above a letter to indicate lenition.
Because it's easier than having to write them all out every time. Also, they get their symbols from their Greek names.
The symbols of a chemical element are abbreviations that are used to denote a chemical element. Typically, they are one or two letters long with the first letter (only) capitalised; temporary names are three letters long.
Hebrew doesn't use symbols. It uses letters. "Randy" in Hebrew letters is ראנדי
zero, all the keys have different letters, numbers, or symbols
Letters.