Searching for duplicated numbers

[ridnickhick]

I input data for a survey company and come across roughly 300 new numbers a day and i have to make sure none of these numbers are duplicated within the day and including any previous numbers i have ever inputted into the spread sheet. Right now my only solution to this task is scrolling through a list of about 10,000 every morning after putting them in descending I watch the last digit in each number and if i ever come across two last digits that are the same then i check the preceding numbers to see if they match. Is there any formula or tool that might help me complete this task more efficiently?

[shg]

Suggesting a formula would require seeing how your data is arranged, but See Help for the COUNTIF function.

[ridnickhick]

I copy all my numbers that i need to check from one sheet and paste them all into column A in *increasing* order of another sheet
Ex.
523-3
581-4
629-5
676-6
694-4
695-3<<<<<this is what im looking for as im scrolling through the spreadsheet
695-3
768-4
778-3

---------- Post added at 02:54 PM ---------- Previous post was at 02:53 PM ----------

I copy all my numbers that i need to check from one sheet and paste them all into column A in *increasing* order of another sheet
Ex.
523-3
581-4
629-5
676-6
694-4
695-3<<<<<this is what im looking for as im scrolling through the spreadsheet
695-3
768-4
778-3

[FDibbins]

assuming your data is in column A, use this formula, it will only show when an exact match is found...

=IF(COUNTIF($A$1:$A$9,A1)=1,"",COUNTIF($A$1:$A$9,A1))

an alternate would be to use the "remove duplicates" if that is an option that could work for you?

[shg]

If you're sorting then anyway,

Please Login or Register  to view this content.

The formula in B2 and copied down is =IF(A2=A1, "oops", "")

If they were not sorted, you could use instead

=IF(COUNTIF(A$1:A1, A2), "oops", "")

That's more resource-intensive.

[day92]

Or you can use conditional formatting. click conditional formatting -- highlight cell rules -- duplicate values.