When you multiply a sequence by X in Python, it doesn't multiply each member of the sequence - what it does is to repeat the sequence X times. That's why X has to be an integer (it can't be a float).
What you want to do is to use a list comprehension:
hh = [[82.5], [168.5]]
N = 1.0 / 5
ll = [[x*N for x in y] for y in hh]