The word arithmetic comes from the Greek word arithmos, which means “number.” The Greeks, however, were not the first people to count or use numbers. Historians think that people began counting objects as early as 10,000 years ago. Ancient people probably developed the idea of counting because they needed a way to know how many animals they owned or how many days had passed since the full moon. Their first step was probably similar to what a child does—using their fingers to count to ten. From there they developed symbols for each of the digits and then a system for writing numbers larger than ten.

After learning how to count, ancient people had to invent addition. If a shepherd had six sheep and was given three more, he had to come up with a quick way to figure out how many sheep he now had. Addition, which seems simple today, is actually a complex idea that probably took centuries or more to understand fully. Subtraction probably came next, followed by multiplication and division.

Many ancient peoples used a simple mechanical calculating device called an abacus. An abacus uses pebbles, disks, beads, or other items as counters. People used this device because their systems of writing numbers were too complex or confusing when used for counting and calculating.

In about AD 700 the Hindu people of India developed a simple system for adding written numbers. The Arab people used this easy-to-use Hindu system, and the Europeans learned it from them. After a few changes, the numerals 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9 caught on and became standard.

Today most people no longer need to use their fingers or an abacus to solve problems in arithmetic. Inventions like adding machines, calculators, and computers now do arithmetic very quickly. Even so, learning arithmetic is essential to understanding mathematics.