I have a timesheet that's used for payroll purposes.  The sheet is about as
simple as it can get.

I would like to be able to enter the time worked for XXXXXX as a decimal
number and have it display as hours and minutes.  For example:

4.5 hours would display as 4:30
2.1 hours would display as 2:06

For any computation of the time, such as adding the two time examples above,
the calculations would work with the original decimal numbers, and the total
would yield 6.6 hours of time.  Yet the display in the cell would be 6:36

You would think this would be a relatively easy thing to do, possibly with
the custom number format.  But I've not been able to find any explanation of
the custom number formatting process that I understand, nor have I been able
to locate an example.

Is it easy to do?  How do you do it?  I would prefer NOT to have to have
hidden rows and columns, or any spiffy basic programming involved, as I would
like to pass on the finished product to others who know even less about Excel
than I do.   :-)

Thanks.

Ken