Count only nonduplicate number

[B Call]

What is the formula that is required to return a count of numbers in a given
range while ignoring duplicate numbers?

For example, a column contains the following numbers:
1
2
2
3
3
3

The count, ignoring duplicates is 3. What is the formula will return this
value?

Thanks.

 

[Frank Kabel]

Hi
try
=SUMPRODUCT((A1:A100<>"")/COUNTIF(A1:A100,A1:A100&""))