# Operators

Sass supports a handful of useful `operators`

for working with different values. These include the standard mathematical operators like `+`

and `*`

, as well as operators for various other types:

`==`

and`!=`

are used to check if two values are the same.`+`

,`-`

,`*`

,`/`

, and`%`

have their usual mathematical meaning for numbers, with special behaviors for units that matches the use of units in scientific math.`<`

,`<=`

,`>`

, and`>=`

check whether two numbers are greater or less than one another.`and`

,`or`

, and`not`

have the usual boolean behavior. Sass considers every value “true” except for`false`

and`null`

.`+`

,`-`

, and`/`

can be used to concatenate strings.

## Order of Operations

Sass has a pretty standard order of operations, from tightest to loosest:

- The unary operators
`not`

,`+`

,`-`

, and`/`

. - The
`*`

,`/`

, and`%`

operators. - The
`+`

and`-`

operators. - The
`>`

,`>=`

,`<`

and`<=`

operators. - The
`==`

and`!=`

operators. - The
`and`

operator. - The
`or`

operator. - The
`=`

operator, when it’s available.

### SCSS Syntax

```
@debug 1 + 2 * 3 == 1 + (2 * 3); // true
@debug true or false and false == true or (false and false); // true
```

### Sass Syntax

```
@debug 1 + 2 * 3 == 1 + (2 * 3) // true
@debug true or false and false == true or (false and false) // true
```

### Parentheses

You can explicitly control the order of operations using parentheses. An operation inside parentheses is always evaluated before any operations outside of them. Parentheses can even be nested, in which case the innermost parentheses will be evaluated first.

### SCSS Syntax

```
@debug (1 + 2) * 3; // 6
@debug ((1 + 2) * 3 + 4) * 5; // 65
```

### Sass Syntax

```
@debug (1 + 2) * 3 // 6
@debug ((1 + 2) * 3 + 4) * 5 // 65
```

## Single Equals

Sass supports a special `=`

operator that’s only allowed in function arguments, which just creates an unquoted string with its two operands separated by `=`

. This exists for backwards-compatibility with very old IE-only syntax.