Sixty-five million sound like a big deal by any standard. That's the size of the improvement that an online army of collaborating mathematician has already made to a groundbreaking proof involving pairs of prime numbers,which was first announced just a few weeks ago.Though the improvement is big,mathematically speaking it amounts to a technicality.Still,the achievement showcase a new way of doing mathematics online.Since the proof appeared,mathematicians from across the world have been locked in an addictive race to tighten it up.