Highlight cell on one sheet if the exact number is in a range of cells on another sheet

Hello All,

Don't know why this one has stumped me, but I can't get it right and keep getting the N/A error.

I have a row of cells on sheet one that have different values (item numbers) in Column A. Can be as few as 15, as many as 500. I have a second sheet on the same workbook that has another list of numbers (random order).

I'm trying to conditionally format the cells on sheet 1 to highlight if that specific number appears anywhere in the range on sheet 2 (to find duplicates). I can't seem to get this right.

Thank you!

I have attached a sample sheet. I'd like to run a conditional formatting rule that would highlight any cell on sheet: Data 1 that also shows up anywhere in column A of sheet: Data 2.
Essentially I'm looking for conditional formatting that will highlight duplicate entries from a different sheet.

I apologize for the lack of clarity. Good catch. Yes, just from column A

I solved this. If anyone needs the solution it is something like this:
(Apply conditional formatting to range of cells you are searching)

=ISNUMBER(MATCH(A1,......))

Fill in with the worksheet and range you are trying to match.