1 Select all the cells in the worksheet (or at least the area you are using)
2 On the Home tab, click the launcher arrow on the Font group label and open
the Format Cells dialog;
open the Protection tab and uncheck the "Locked" box to unprotect all cells
3 On the Home tab, locate the Find & Select group at far right and click it;
click on Go to. In the Go To dialog check the "Formula" box. Now again use
the Home tab, click the launcher arrow on the Font group label and open the
Format Cells dialog; open the Protection tab and uncheck the "Locked" box to
protect all cells having formulas
4 In the Review tab in the Changes group, click Protect Worksheet. In the
resulting dialog there is a list under "Allow all users of the worksheet
to:" -- make sure only "Select Unlocked Cells" is checked
best wishes