How many perimeters (circuits or laps) of the playgrounds is equivalent to 50km?

Year 6/7 investigated the length of the perimeter of the playgrounds using trundle wheels, measuring tapes and metre sticks. We  found the trundle wheels the easiest to use for this task. We found the average length of one circuit of the playgrounds was 128m, which means we’d need to walk (or run) 391 of them to complete a distance of 50km. Will we be able to walk 50km before Easter? Can you work out how many circuits we’d need to do per day to reach our target before Easter?