Remove formula from pages table

I am creating an invoice for a client using the pages provided invoice template with table. I am wanting to modify one of the columns to show a percentage (of overall time/payment). When I enter the number and percent symbol (20%) + enter it automatically turns into $ 0. I don't even necessarily need the column to do the calculation of time. I just need to show the client what percentage it is and what that cost is in the next column. How do I go about removing the "function" from these columns?

TIA.

Krysten