### Numeration Decimal System

Many towns used stones with the same object; in America the Peruvian Incas used cords with knots, to take their accounting and they called quipos to him. With passing of the time it invented the portable abacus which consisted of small balls ensartadas in a cord that to their time paid attention to a wood support. Today in our days these abacuses are obtained, but the small balls pay attention to supports of wood or wires. Thanks to the discovery of the abacus the businesses could work in the old world and with certain agility, which were worth of this ingenious tool to realise their calculations and mathematical operations. The use of the abacus extended by all Europe until the Average Age, but when the Arabs implant the numeration system decimal the use of the abacus began to decline. Of the use of the abacus in our times an anecdote in 1.946, that is very important to enunciate, in that one year exists was realised a competition of rapidity of calculation between a North American and a Japanese, the American used a calculator and the Japanese used an abacus; the competition was gained by the Japanese. 1.2 THE NUMERATION DECIMAL SYSTEM. In the times of the conquest of Daro and the expeditions of Alexander, which put to India in contact with the civilizations of the Next East and Greece.

The Indian mathematicians already knew the use the babylonian system of numeration by position. The Hindus adapted to the numeration decimal, and created therefore the decimal system of position, which we know in our days. For a fact one does not know with exactitude when it was the invention of this system, but one assumes that he was between centuries II and I SAW D.C, but was not but until century XII that were introduced in Europe and of there they arrived until the Arab mathematicians who went those that they got to preserve, to compile and to transmit a knowledge of which they were not the true authors.