Cricle and Square: Group show

John and Michael, the twins whose case is described by the neurologist Oliver Sacks, didn’t know how to add, divide or perform the most basic mathematical procedures, for example, answering what is 3 times 7. However, they could memorize huge numbers just by listening to them once, recognize the prime numbers in figures of more than six digits and state without mistake, what day of the week would be any date that would be requested to them in a range of 40,000 years ahead and 40,000 years back. The scene with the matches is classic, and Oliver Sacks' narrative is astonishing:

A box of matches on their table fell, and discharged its contents on the floor: '111,' they both cried simultaneously; and then, in a murmur, John said '37'. Michael repeated this, John said it a third time and stopped. I counted the matches - it took me some time - and there were 111.