Termporarily--just for this report or permanently--number stays with "title" always.
To temporarily number the titles--assuming that each title is in a different record, enter layout mode, click the text tool and then click to the left of the title field. Select "Record Number Symbol" from the Insert menu. Return to browse or preview modes to see the numbering appear.
Note that the actual text inserted on your layout is different in FileMaker 12 from the @@ inserted in older versions, but the result is the same.