An hour is equal to 60 minutes. Half an hour is 30 minutes.
We can break "8.5" into 8 hours and 0.5 of an hour (which is 30 minutes).
Knowing this, we can multiply 8 by 60 since each hour is 60 minutes. We then get 480. We still need to add the remaining 0.5 of an hour (30 minutes) so we add 480 + 30. We then get 510.
Therefore 8.5 hours = 510 minutes. Hope this helps!
