Hours   Minutes   0.05     3   0.10     6   0.15     9   0.20   12   0.25   15   0.30   18   0.35   21   0.40   24   0.45   27   0.50   30

Hours   Minutes   0.55   33   0.60   36   0.65   39   0.70   42   0.75   45   0.80   48   0.85   51   0.90   54   0.95   57   1.00   60

A total amount of hours may sometimes be confused as hours and minutes.
For example, 7.45 hours could be mistaken to mean 7 hours and 45 minutes.
Actually, those .45 hours when multiplied by 60 are converted to 27 minutes.
Even easier is to use the above chart and as you can see .45 hours = 27 minutes.