Is there a way within excel to clear a sheet of all numbers, but leave behind text and formulas?

To elaborate: I mean cells that contain ONLY numbers. If a cell contains text and numbers (like "Period 1") it can stay.

Edit: Just to be clear: I'm not asking for the values that formulas evaluate to to remain. that would be silly. I am asking for the formulas themselves to remain. the text of the formula. So that the zeroed page still has formulas ready for data to be added to the zeroed cells. and produce the result of the formula.