Our number system is based on the Hindu-Arabic number system, which was based on place value (using 0 as the place holder) and whose symbols were the precursors of the digits 0 to 9. The Hindu-Arabic number system was thought to have originated in India, reaching Western Europe through the Arab occupation of Spain. It was gradually adopted during the Middle Ages, replacing the unwieldy number system of the Romans.

The following are fruitful areas for research and investigation:

• Examination of Roman and Greek alphanumeric systems reveals that they did not lend themselves to the development of arithmetic.
• The symbol 0 was probably first used in India, where our base-10 place-value system originated. (The Hindu word for zero is sunya and the Arabic is sifra, which means ‘empty’. In 1202 an Italian mathematician called Leonardo Fibonacci, studying Arabic methods, wrote about the sign 0 being called ‘zephirum’. This is where our word for zero comes from.)
• The Babylonians used base 60. Their numerals were constructed from the two basic symbols for 1 and 10. We retain clear traces of this system today in our measurement of time and angle.
• The Mayan place-value system used base 20, but modified to tie in with their highly developed calendar. They used bars for 5s and dots for 1s and had a number of symbols to represent the absence of a unit, i.e. for 0.
• Chinese ‘rod’ numerals (composed of strokes) used base ten and place value, with calculation carried out on a chequered board. Zero was introduced later, possibly as a result of contact with India.
• Egyptian and Cretan systems were based on repetition of symbols for 1, 10, 100 and so on.
• The electronic calculator is a modern equivalent of counting boards, the abacus, the Japanese soroban (still widely used), Napier’s ‘bones’, logarithms, the slide rule, and other mechanical calculating machines developed by previous generations.