You are right in what you are doing IF you work 7 days a week. Me ..no, I work 5 days a week.
So if cell A2 contains the hours worked you can get the Days worked in cell B2 with the formula
=A2/8
If you want whole days only then make that
=INT(A2/8)
To get the number of weeks worked in cell C2 use formula
=A2/8/5
or if you want whole weeks only use
=INT(A2/8/5)