This second scenario is if you wish to sum all the values in the one field, i.e. for either a continuous form or in a report.
To do this:
Add an unbound text box to the form or the report.
In a continuous form you would normally (but not always) put this in the form footer.
On a report you would normally (but not always) put this in the footer of the section of a grouped report where the field is you would like to add together.
To this unbound text box add the following formula:
=Format(Sum([TimeExamples])*24,"#.0") & " Hours"
These formats will display the result as: 136.8 hours. The results are rounded and the final part is in decimals, so you may wish to change these back to minutes, depending on what you are going to do with the result.