Necessity, that Mother of Invention

So we are training for some upcoming races and have been wanting to know exactly how many miles we run on certain trails.  Marc wanted to get a bicycle odometer for easy measuring, just £14.99  at the bike shop down the street.  

Fifteen pounds to measure a distance once?  I couldn't stomach it and said no way.    

So Marc got creative.  He taped a scrap of cardboard to the spokes of his bike, so that each time the wheel went around you could hear a whap.  He then proceeded to ride the trails, counting the number of whaps and making a quick tally mark (one for every 30 whaps) on a piece of cardboard taped to the handlebars.  A few mathematical equations later, we knew all the distances we need to know!  The loop around the castle grounds then along Beehive Hill to the wheat fields and through Crackley Wood and back through Parliament Piece is 6.7 miles, just so you know.   And you thought you couldn't use math in real life...