// Invert number
@function number-invert($number) {
	@return $number * -1;
}
@function invert($number){
	@return number-invert($number);
}


// Round (shortcut)
@function decimal-round($number, $digits: 0, $mode: round) {
	$n: 1;
	// $number must be a number
	@if type-of($number) != number {
		@warn '#{$number} is not a number.';
		@return $number;
	}
	// $digits must be a unitless number
	@if type-of($digits) != number {
		@warn '#{ $digits} is not a number.';
		@return $number;
	} @else if not unitless($digits) {
		@warn '#{$digits} has a unit.';
		@return $number;
	}
	@for $i from 1 through $digits {
		$n: $n * 10;
	}
	@if $mode == round {
		@return round($number * $n) / $n;
	} @else if $mode == ceil {
		@return ceil($number * $n) / $n;
	} @else if $mode == floor {
		@return floor($number * $n) / $n;
	} @else {
		@warn '#{$mode} is undefined keyword.';
		@return $number;
	}
}
@function round($number, $digits: 0, $mode: round){
	@return decimal-round($number, $digits: 0, $mode: round);
}

// Ceil (shortcut)
@function decimal-ceil($number, $digits: 0) {
	@return decimal-round($number, $digits, ceil);
}
@function ceil($number, $digits: 0){
	@return decimal-ceil($number, $digits: 0);
}

// Floor (shortcut)
@function decimal-floor($number, $digits: 0) {
	@return decimal-round($number, $digits, floor);
}
@function floor($number, $digits: 0){
	@return decimal-floor($number, $digits: 0);
}