# THE PERCENSIVE ABACUS IN HISTORY

An important fact on this context is The geometric reasonings that could be extracted they were depending, logically, on the precision of the lines. For this reason, the Latin poet Persio, in one of his writings, compares the skill of the poet when it measures the metrics of his poems with that of the geometer on having planned his lines on the sand of ábaco2.

This technology was much applied by the Romans, owed, they had to solve his handling of revenue of goods and the handling of the first coins, due to his colonies and route of commerce, they organized themselves by means of this instrument, the numeral signs recorded in the bronze express the value represented by the pieces of every column. This way, four cards placed in the second long groove beginning for the right hand represent units the (I)st, the placed ones in the third groove dozens the (X)th, those of the fourth hundreds (C), those of the country house thousands, those of the sixth dozens of thousand, those of seventh hundreds of thousand and those of the octave units of million (IXI), the cards in the short grooves of the top part represent the groupings of five, that is to say: 5 units, 5 dozens.

gives him more understanding the meaning of the grooves and remaining cards we must tell that these abaci were used preferably for the calculations of monetary character. The unit dineraria Roman was the expert, the expert was splitting into 12 ounces and to this unit the first long groove refers (O) and his top continuation: five low cards represent each of them an ounce, whereas the card of the top groove symbolizes six ounces. Finally three small grooves of the right hand of the table correspond to the monetary units of minor value of the Roman system and come represented by fractions of ounce: half an ounce (S), a quarter of ounce and a third of ounce (Z). Since it is logical, only the groove of the thirds of ounce needs from two mobile cards.

your way of mathematical employment was located of the following form, had to be located in horizontal position with all the cards placed in the low end of every groove. To represent a quantity it was enough to displace it towards the top part or the cards corresponding to the units, dozens, hundreds.

your limitante of his employment in the history, before of taking record documented properly in reference of taking a numerical art, of any deal in the application of this instrument, is the representation of numerical quantities in these instruments it turns out to be very easy to understand and also very illustrative on conceptual, such aspects as the formation and composition of the number, by which his didactic use is recommended in the school. On the other hand, the achievement of operations is not a task so easy to understand and less of realizing.

To The moment to do calculations, in which necessarily they take control of several numbers, certain skill is needed, both of visual memory, and of mental calculation.

the following thing Is necessary to realize well all this leaves the following thing for the life of the knowledge, the arithmetic, geometry, astronomy, like a collision to learning of two branches of the mathematics. Realizing well following the traditional algorithms we appreciate several important differences. First of all, the use of the board is a slower and laborious procedure than the algorithms.

Departing from this instrument and his technology they defined cultural culture, knowledge, societies, mass media, changes, in which they were evolving with the time, opened ways for new knowledge, at present digital calculator and adding machine exists, which they apply functions of calculations and arithmetic, more simplified, that facilitate our daily life and the way of seeing the things and his use, it is not necessary to lose the precedent of the history, that defined our present in the mathematical world and his technological application, that nowadays defined our present, since the mathematical calculation is supported applying, up to the point every day you are born new applications as tool to solve conflicts.