Just got home from work to have my 18 yr old son tell me about the numberphile video proof. We watched the video and I told him immediately that the false step was stating that 1-1+1-1... = 1/2. That series sum fluctuates between 0 and 1 and can never equal 1/2. The average is 1/2. Thanks for posting this article because he was falling for the magician's trick.