If we weren't afraid to confuse our Greek readers, we could just use greek letters: ω (=0) α β γ δ ε ζ η θ ι κ λ, with ' to indicate a number: 15 would be writt

If we weren't afraid to confuse our Greek readers, we could just use greek letters: ω (=0) α β γ δ ε ζ η θ ι κ λ, with ' to indicate a number: 15 would be written 'αγ. But see: https://en.wikipedia.org/wiki/Greek_numerals https://en.wikipedia.org/wiki/Greek_numerals