My grandfather (born around 1910, died 1969) used to earn extra money on week ends by going to the horse track and calculating odds for the bookies. They’d tak

My grandfather (born around 1910, died 1969) used to earn extra money on week ends by going to the horse track and calculating odds for the bookies. They’d take a big bet and he would tell them how to adjust the odds and what offsetting bets to make to hedge risk. This was in guineas, pounds, shillings, farthings etc. He did all the calculations in his head. He’d only attended school through part of year 5. Not surprisingly, the one of his kids who went to uni (my dad) got two maths degrees and two EE degrees.