Arithmetic: Elementary branch of mathematics

The four basic arithmetic operations are addition, subtraction, multiplication, and division, although other operations such as exponentiation and roots are also studied in arithmetic.

Other arithmetic topics includes working with negative 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, 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.

• ${\displaystyle 2+3=5}$  (addition is commutative: ${\displaystyle 2+3}$  is the same as ${\displaystyle 3+2}$ )
• ${\displaystyle 7-5=2}$  (subtraction is not commutative: ${\displaystyle 7-5}$  is different from ${\displaystyle 5-7}$ )
• ${\displaystyle 3\times 4=12}$  (multiplication is commutative: ${\displaystyle 3\times 4}$  is the same as ${\displaystyle 4\times 3}$ )
• ${\displaystyle 6/2=3}$  (division is not commutative: ${\displaystyle 6/2}$  is different from ${\displaystyle 2/6}$ 

• Affine arithmetic
• Elementary algebra
• Interval arithmetic
• Modular arithmetic