Index: help/C/gcalctool.xml
===================================================================
--- help/C/gcalctool.xml	(revision 1843)
+++ help/C/gcalctool.xml	(working copy)
@@ -1646,6 +1646,11 @@
 		  </tgroup>
 		</table>
     </sect3>
+    <sect3 id="gcalctool-calc-bit-manipulation-ext">
+      <title>To Perform Bit Manipulations on Integers</title>
+      <para>To change the values of individuals bits in integer values, choose <menuchoice><guimenu>View</guimenu><guimenuitem>Show Bitcalculating Extension</guimenuitem></menuchoice>. This option is only available in Scientific mode.</para>
+      <para>If the calculator display shows an integer value, then each of the bits in that integer value is displayed as a collection of 0's and 1's. By clicking on any of these individual bits, their value can be toggled, causing the displayed integer value to be adjusted accordingly.</para>
+    </sect3>
     <sect3 id="gcalctool-enter-exp"> 
       <title>To Enter Exponential Numbers</title> 
       <para>To enter exponential numbers, use the <guibutton>Exp</guibutton> button.</para>
