Mental abacus

The mental abacus system is a way to calculate math in your head, by imagining an abacus. People can calculate math very fast this way.  For example, using this method, Takeo Sasano was able to add fifteen three-digit numbers in just 1.7 seconds.

This system is being used in China, Singapore, South Korea, Thailand, Malaysia, and Japan. 

The abacus can be used to do addition, subtraction, multiplication, and division. It can also be used to get square and cube roots.

 Related pages 

 Abacus

 References 

 Other websites 

 Mental abacus does away with words, New Scientist, August 9, 2011

Category:Mathematics