match randomly selected rows of data

Hello all,
Hopefully I can explain what's in my head clearly enough

Sheet 1 - dataset, including an ID number on each row (from 1 to 10000)
Sheet 2 - already randomly selected 10% of those ID numbers, so we've got a column of 1000 numbers all between 1 and 10,000

I'd like to be able to indicate on sheet 1 which ones have been randomly selected, so I can filter accordingly.
(For example, by adding a column and some kind of 'if this ID number is listed on sheet 2, then add 'TRUE' type equation, but open to best suggestions)

I imagine this is prob very simple if-you-know-how, but my brain isn't kicking into gear. Any help much appreciated!

Cheers,
Mike

Thanks for the quick response. Should have clarified before, not a VBA user (as in, never have used it before).
Is there a simple IF formula I can use for this?

See sample attached.

Basically, in the 'data' tab, how can I indicate in column B that the ID number was selected for further review?

The selected ID numbers are in the 'random' sheet.

Many thanks

That's perfect, many thanks!