Delete all input cells, but keep the formulas
Your worksheet may be set up with formulas that operate on a number of input cells. Here's an easy way to clear all input values while keeping the formulas intact.
Press F5 to display the Go To dialog box, and click the Special button. In the Go To Special dialog, choose the Constants button and select Numbers. When you click OK, the nonformula numeric cells will be selected. Press Delete to delete the values. The Go To Special dialog box has many other options for selecting cells of a particular type