In ancient Rome they used the following units of length:
5 pedes = 1 passus,
125 passus = 1 stadium.

The atrium (courtyard) of Marcus' home was a square with each side 50 pedes long.

How many times did Marcus have to walk round his atrium to complete his daily exercise of 8 stadia?
 

If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.