Åk 6–9

English
 1.2 History The need to be able to express the quantity of something has existed far back in human history.  To be able to count cattle, goods, and money would be impossible without using numbers.  Man, therefore, created a way of writing numbers. The simplest way to represent a quantity was to draw vertical lines in a row next to each other. Each line could for example represent a cow or a measure of grain. l l l l l l l l l This simple numbers system was developed upon further when the number of cows, sheep or measures of grain became too many. Instead of drawing several lines, different figures were used to represent instead the quantity of lines. These lines were “replaced” by a symbol. About 5,000 years ago, the Egyptians used for example the following symbols to represent quantities.  The Babylonians (3000 - 2000 BC) used, on the other hand, a position system which was not too different from our way of writing numbers but instead is used the base 60. A further development came about 2,000 years ago when the Mayans, who lived in Central America, began using what we call an additive position system with a base of 20. In their number system, they could even represent the number zero. The Roman number system or numeral system, which began being used around 300 BC, uses roughly the same idea; however, they added the restriction that the same symbol could only be used a maximum of three times in a row. The Romans numerals have even been popular in more modern times to designate the year that a building was constructed.