Question

who is invented Abacus in 3000 B.C​

Answer 1

Answer:

People used to count on fingers or used pebbles or twigs for larger numbers. Gradually counting devices came into existence and abacus was one such device.

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History Of Abacus.

3000 BC: An early form of abacus finds its origin in China.

500 BC: Counting boards are used by Romans and Greeks.

Answer 2

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Tim Cranmer

An adapted abacus, invented by Tim Cranmer, called a Cranmer abacus is still commonly used by individuals who are blind. A piece of soft fabric or rubber is placed behind the beads so that they do not move inadvertently. This keeps the beads in place while the users feel or manipulate them.