Be careful when using groups because if you forget that your spreadsheets are grouped and then proceed to add or change figures on a worksheet, all of the worksheets in the group will have the same figures. To remove a group, simply click on a sheet that is not in a group. If all of the worksheets are grouped, right_click on any tab and choose Ungroup Sheets. Keep an eye on the title bar prior to making changes and Excel will tell you if the sheets are grouped.
Then along came digital copiers and the purple_ink mimeograph machine disappeared. But the teaching tool that the mimeograph machine spawned _ the worksheet _ has lived on... and on... and on. For decades _ literally decades _ teachers have been enamored with worksheets. So what is the bottom line? Are worksheets a serious teaching tool or an over_used form of busy work? The answer, of course, is both.