Number updated by selection of choice column

I have two columns, one is a Number column (_x0023_ofGuests)and the other is a Choice column (Closed).

User can enter a number between 1 and 300 for the Number column and one of the choices in the Choice column is "Non-actionable".

I would like to have the Number column changed to blank " " if the choice column has a value of "Non-actionable", otherwise keep the number value that was entered by the user.