Number System

• There are two popular numeral systems:
  • The Arabic system
  • The Roman system

Arabic Numerals

• The numerals we use today in calculations are known as Hindu-Arabic numerals.

Invention of Zero and the Hindu-Arabic Numbers

• Ancient Hindu mathematicians are believed to have invented the Arabic numerals, which were later adopted by the Arabs. The Arabic system of numbers was used as early as the 5th or 6th century BC, but zero was not used with these numbers at that time.

The system was brought to Europe from the Arabs around the 10th century and replaced the Roman system. These numbers were called Arabic numerals.

The zero was invented by the Hindus around 876 AD. It was represented by a small circle called ‘Shunya’, which means ‘vacant’ in Sanskrit.

The Italian mathematician Leonardo Fibonacci (1170-1240) popularized the Arabic system of numerals in his book ‘Book of the Abacus’, published in 1202.

The word ‘digit’ comes from the Latin word ‘digitus’, which means ‘finger’. This is because people used their fingers to count in the past.

The decimal system, which is based on powers of 10, also originated in India around 1000 BC. It was later popularized by a Flemish mathematician named Simon Stevin in the 16th century. In 1585, a mathematician named Simon Stevin (1548-1620) wrote a book called “De Thiende” (The Tenth). Before this book, numbers less than one were written as fractions.

The Romans used a different number system called Roman numerals about 2000 years ago. This system used letters from the English alphabet to represent numbers. There were seven basic symbols:

1. I = 1
2. V = 5
3. X = 10
4. L = 50
5. C = 100
6. D = 500
7. M = 1000

There was no zero in the Roman numeral system. The system worked based on the following rules:

• Repeating a letter repeated its value. For example, XX = 20 (10 + 10).
• A letter placed after a letter of greater value added to the value. For example, VI = 5 + 1 = 6.
• A letter placed before a letter of greater value subtracted from the value. For example, IV = 5 - 1 = 4.
• A dash over a number multiplied its value by 1000. For example, X = 10 x 1000 = 10,000.

Here are some examples of how Roman numerals work:

1 = I 2 = II 3 = III 4 = IV 5 = V 6 = VI 7 = VII 8 = VIII 9 = IX 10 = X 11 = XI 12 = XII 13 = XIII 14 = XIV 15 = XV 16 = XVI 17 = XVII 18 = XVIII 19 = XIX 20 = XX