There was evidence of the abacus going back as early as 2700 B.C. And it is still commonly used in certain countries and places like Japan, China, Russia, and the Middle East.
Yes.
yes but not many people use it
The minimum number of bars on an abacus is nine. An abacus is a calculating tool that was used before the written numeral system came into use. It is still used by merchants and traders in countries in Asia and Africa.
Before electronics were invented, Mathematicians used abacus's.
The abacus was used in Russian even as late as 1976 in grocery stores in Moscow. Basically any country that does not have access to a cheap pocket calculator. I'm sure you can find many places in third world countries that use it for business transactions. It needs no batteries and when used by a person proficient in abacus, it can provide a correct answer as quick as a calculator.
Yes abacus still in used today, specially for visual impaired students. Eventhough the talking calculator did help for visual impaired students at Braille schools across the nation, but talking calculator do not let students understand the important of number placement value. I enclosed some websites talk about the benefits of using abacus in Braille schools: http://www.hadley-school.org/resources_list_detail.asp?resource=abacus http://www.hadley-school.org/resources_list_detail.asp?resource=abacus
The Abacus.
The Abacus.
The Abacus.
An abacus measures nothing, it is a device used for calculation
The Sumarian abacus appeared as early as 2700 BC, The ancient Egyptians and the Persians also used the abacus