Adding a unit to a number in Sass

I am trying to create dynamic values, but have failed so far. The created pixel value seems to lose the ability to be used in calculations.

$numericValue: 30;

$pixelValue: $numericValue+px;
// also tried $pixelValue: #{$numericValue}px;

$calc: $pixelValue * 2;
// also tried $calc: unquote($pixelValue) * 2;

This throws an error

Syntax error: Undefined operation: "30px times 2"

Solution 1:

The trick is to use * 1px when you want to add a unit. Using +px or interpolation (#{$numericValue}px) turns it into a string.

$numericValue: 30;

$pixelValue: $numericValue * 1px;

$calc: $pixelValue * 2;