I posted a question earlier and I think my final question got lost. I'm
using the following formula to count the number of letters in a cell:

=SUMPRODUCT(LEN(SUBSTITUTE(A22,{0;1;2;3;4;5;6;7;8; 9},"")))-9*LEN(A22)

You all were kind enough to explain how the functions work but I still dont
understand why you subtract 1 less than the number of arguments in the
substitute formula and then multiple it by the lenght.

Thanks again for all you help.