How do I set the number format to Base 12?

I would like to change the number format on my spreadsheet from Base 10 to
Base 12, eg. 12 bottles makes up 1 case. Therefore, if I were adding up three
different cells 9 bottles + 11 bottles + 6 bottles, my result should be 2
cases 2 bottles if possible 2.2 in a case column.

See http://www.cpearson.com/excel/fractional.htm for details.


--
Cordially,
Chip Pearson
Microsoft MVP - Excel
Pearson Software Consulting, LLC
www.cpearson.com


"Andrew Moore" <AndrewMoore@discussions.microsoft.com> wrote in
message
news:893CABE9-37D7-4E6B-8A7E-A5E679C8C824@microsoft.com...
>I would like to change the number format on my spreadsheet from
>Base 10 to
> Base 12, eg. 12 bottles makes up 1 case. Therefore, if I were
> adding up three
> different cells 9 bottles + 11 bottles + 6 bottles, my result
> should be 2
> cases 2 bottles if possible 2.2 in a case column.