In Excel 2011 for Mac OS X, after installing ChemUnits Add-In you must select Add-Ins using the Tools menu.

In the Add-Ins dialog that appears, select the ChemUnits Add-In. Click OK and ChemUnits is ready to use.

Science and Engineering Calculators
In Excel 2011 for Mac OS X, after installing ChemUnits Add-In you must select Add-Ins using the Tools menu.
In the Add-Ins dialog that appears, select the ChemUnits Add-In. Click OK and ChemUnits is ready to use.