Excel 2007 : Constructing a formula that counts distinct words in a single cell

If you only have single digits as per your example then this formula will count them

=COUNT(FIND({1,2,3,4,5,6,7,8,9,0},A1))

Indeed, a better alternative

I guess if you have 2 or 3 digit numbers too.. then you can use:

=COUNT(FIND(ROW(INDIRECT({"1:1000"}))-1,A1))

confimed with CTRL+SHIFT+ENTER...

Change 1000 if larger than 3-digit numbers can be found