# 0123456789   Arabic Numerals   9876543210

Arabic Numbers --- Introduction --- Add --- Subtract --- Multiply --- Divide --- Practise sums --- Less than 1 --- Types of numbers

Arabic numerals are the 'normal' numbers used for arithmetic. They are also known as decimal numbers, since they are base 10, unlike binary and other number bases.

Arabic numbers are also called Hindu-Arabic numbers. This is a better name as it was the Hindus in India who invented the system from about the 4th century BC onwards. This number system spread to the Middle East in about the 9th century AD, where it was used by Arab mathematicians and astronomers. (Muslim scientists used the Babylonian number system, and merchants used the Abjad numerals, a system based on letters, rather like Greek numbers.)

Arabic numbers then spread to Europe. Before this, Europeans were using Roman numbers, with abacuses for calculation. Fibonacci wrote a book about Arabic numbers in the thirteenth century AD. At first, these numbers were very unpopular in Europe, since people were used to using abacuses where you could watch the calculation taking place. But they soon realised how much easier it was to do calculations with Arabic numbers.

Now Arabic numbers are generally used throughout the world for calculation, although systems such as Roman, Greek and Chinese are still used for formal purposes.