Verified answer

If you want to check if the numbers in one list is on another list, use match function

Say the longer list is A1:A500 of Sheet1, short list is C1:C200 of Sheet2

To check every name in short list put this formula in D1, then copy it down to D200

=MATCH(C1, Sheet1!A$1:A$500,0)

if those cell in C1:C1000 has a match, a integer will show up otherwise, #N/A

To check every name in long list put this formula in B1, then copy it down to B500

=MATCH(A1, Sheet2!C$1:C$200,0)

if those cell in A1:A500 has a match, a integer will show up otherwise, #N/A

Note: the integer show up is the row number of the table where the name matches