The Shanghai Card is a mathematical poker card game in which the object is to find a way to manipulate four integers so that the end result is 24. Addition, subtraction, multiplication, or division may be used to make four digits from one to thirteen equal 24. For an example card with the numbers 4,7,8,8, a possible solution is the following: 8/8=1, 7-1=6, 6×4=24.
This Chinese game requires skill at mental arithmetic. It has been played in Shanghai at least since the 1960's, and it is also known in some other cities, for example in Qingdao and Guangzhou. Since the end of the 20th century it has also spread to some places in North America.… Expand