<p class="Paragraph">In the default <help:productname xmlns:help="http://openoffice.org/2000/help">%PRODUCTNAME</help:productname> displays three sheets "Sheet1" to "Sheet 3" in each new spreadsheet.</p>
<p class="Paragraph">In the context menu, use the <span class="T1">Insert Sheet</span> command to insert either a new sheet or an existing sheet from another file in front of the active sheet.</p>
<p class="Head2">Select multiple sheets</p>
<p class="Paragraph">The sheet tab of the current sheet is always visible in white in front of the other sheet tabs. The other sheet tabs are gray when they are not selected. By clicking other sheet tabs while pressing <help:switch select="System" xmlns:help="http://openoffice.org/2000/help"><help:case select="MAC">Command</help:case><help:default>Ctrl</help:default></help:switch> you can select more sheets.</p>
<p class="Head2">Undo selection</p>
<p class="Paragraph">In order to undo the selection of a sheet, click its sheet tab again whilst pressing the <help:switch select="System" xmlns:help="http://openoffice.org/2000/help"><help:case select="MAC">(Command)</help:case><help:default>(Ctrl)</help:default></help:switch>-key. The current sheet that is visible cannot be removed from the selection.</p>
<p class="Head2">Write values simultaneously to multiple sheets</p>
<p class="Paragraph">If multiple sheets are selected, all values entered into the active sheet will automatically be inserted in the other selected sheets (i.e., data entered in Sheet 1, cell A1 also appears in the same cell of Sheet 2).</p>
<p class="Head2">Calculate function across multiple sheets (e.g. the mean of cell A1 across all sheets)</p>
<p class="Paragraph">Enter the formula as follows: =MEAN(Sheet1.A1:Sheet50.A1). In the formula cell the mean is now shown across all the A1 cells of your 50 sheets.</p>