Google has a feature for their spreadsheets that allows you to protect a cell or range of cells from being edited. The protection is granular and can be customized to the point where you can choose exactly who can and cannot access cells. The embedded video at the end of this post shows how to do this. Here are the steps.
Highlight the cells or range of cells that you want to protect
Right-click and choose “Protect range…”
After choosing Protect range, you have the option of naming the range or you can leave it as is. Note that you can also protect an entire Sheet (or Tab) from this dialog box as well. In the screen shot below, I will name the range Management Only to denote that only the people that boss you around are allowed to modify these cells.
Use the dialog on the right hand side of your screen to adjust the specifics.
Specify a cell or range of cells here, give it a name, and decide who can and who cannot have access.
Note that you can only set permissions for specific users if they have already been invited to view the spreadsheet before you perform this function.