5-1400 A.D.	The Apices, the coin-board and the Line-board are developed from 5 A.D. to 1400 A.D. .
1300 A.D.	The 2/5 abacus (2 on the upper part, 5 on the lower) made its first appearance in Chinese culture.
1600 A.D.	The 1/5 abacus was adopted by the Japanese via Korea. .
1614 A.D.	Scotsman John Napier (1550-1617) invented Napier’s Rods; an ingenious system that allowed multiplications, divisions, square root and cube root calculations. It used a system of movable rods that were placed on a specially constructed counting board.
1623 A.D.	Wilhelm Schickard invented a machine called the Calculating Clock. The system of revolving wheels that represented units and tens were capable of adding and subtracting up to 6 digit numbers. It worked in a similar way to modern day clock counters. .
1625 A.D.	William Oughtred invents the slide rule. It enables multiplication to be carried out quickly and easily.
1642 A.D.	Frenchman Blaise Pascal produces the Pascaline, an adding machine that coped with up to 8 digits.
1668 A.D.	Englishman Sir Samuel Morland builds a complicated adding machine that works with the old non-decimal English monetary system of pounds and pence.
1671 A.D.	Gottfried Leibniz (one of the inventors of calculus), builds The Stepped Reckoner. This multiplication machine can handle up to 5 and 12 digits to give a 16 digit operand. Leibniz's calculating device was found in an attic in 1879!
1775/1776.	The English Earl Charles of Stanhope, and German Mathieus Han, each build multiplying calculators that are similar to Leibniz's.
1775/1776.	J. H. Mueller conceives the idea of a difference engine, a calculator for tabulating values of a polynomial. Due to lack of interest and funding, Mueller's attempt project is forgotten.