Conditional formatting based on selection from a dropdown list

I have a spreadsheet that is used as a sort of a schedule. Each person has their own ID number and the ID number is shown in a distinct cell. So if my ID is 41, I might see myself scheduled 9-12 on one day, etc. The problem is that finding your number over multiple pages and permutations is messy. So I have a dropdown where you can select your number, and I want to have this highlight any occurrences of your ID number on the schedule.

I tried using conditional formatting>use a formula to determine which cells to format> =ISNUMBER(FIND(AT8, C10)) where AT8 is my drop down and C10 is the start of the schedule table.

This works BUT if the person’s ID number is “2” then any cell with a 2 is highlighted (12, 22, etc.). How can I get this to match only the exact value and highlight only cells that exactly match?

Thank you!