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
You need to define the unit you will use. If you are working with pixels you can create dynamic values adding px to the $numericValue.
px
$numericValue
$numericValue: 30px; $pixelValue: $numericValue; $calc: $pixelValue * 2;