**Reference** Language | Libraries | Comparison | Changes

## Addition, Subtraction, Multiplication, & Division

#### Description

These operators return the sum, difference, product, or quotient (respectively) of the two operands. The operation is conducted using the data type of the operands, so, for example, `9 / 4`

gives `2`

since 9 and 4 are ints. This also means that the operation can overflow if the result is larger than that which can be stored in the data type (e.g. adding 1 to an int with the value 32,767 gives -32,768). If the operands are of different types, the "larger" type is used for the calculation.

If one of the numbers (operands) are of the type **float** or of type **double**, floating point math will be used for the calculation.

#### Examples

y = y + 3;
x = x - 7;
i = j * 6;
r = r / 5;

#### Syntax

result = value1 + value2;
result = value1 - value2;
result = value1 * value2;
result = value1 / value2;

#### Parameters:

value1: any variable or constant

value2: any variable or constant

#### Programming Tips:

- Know that integer constants default to int, so some constant calculations may overflow (e.g. 60 * 1000 will yield a negative result).
- Choose variable sizes that are large enough to hold the largest results from your calculations
- Know at what point your variable will "roll over" and also what happens in the other direction e.g. (0 - 1) OR (0 - - 32768)
- For math that requires fractions, use float variables, but be aware of their drawbacks: large size, slow computation speeds
- Use the cast operator e.g. (int)myFloat to convert one variable type to another on the fly.

Reference Home

*Corrections, suggestions, and new documentation should be posted to the Forum.*

The text of the Arduino reference is licensed under a
Creative Commons Attribution-ShareAlike 3.0 License. Code samples in the reference are released into the public domain.