# Arithmetic

elementary branch of mathematics

In mathematics, arithmetic is the basic study of numbers. The four basic arithmetic operations are addition, subtraction, multiplication, and division, although other operations such as exponentiation and extraction of roots are also studied in arithmetic.

Other arithmetic topics includes working with signed numbers, fractions, decimals and percentages.

Most people learn arithmetic in primary school, but some people do not learn arithmetic and others forget the arithmetic they learned. Many jobs require a knowledge of arithmetic, and many employers complain that it is hard to find people who know enough arithmetic. A few of the many jobs that require arithmetic include carpenters, plumbers, auto mechanics, accountants, architects, doctors, and nurses. Arithmetic is needed in all areas of mathematics, science, and engineering.

Some arithmetic can be carried out mentally. A calculator can also be used to perform arithmetic. Computers can do it more quickly, which is one reason Global Positioning System receivers have a small computer inside.

## Examples of arithmetic

• 2 + 3 = 5 (adding is commutative: 2 + 3 is the same as 3 + 2)
• 7 − 5 = 2 (subtracting is not commutative: 7 − 5 is different from 5 − 7)
• 3 × 4 = 12 (multiplying is commutative: 3 × 4 is the same as 4 × 3)
• 6 ÷ 2 = 3 (dividing is not commutative: 6 ÷ 2 is different from 2 ÷ 6