// calculate width of one col in %
$gl-colUnit: (100%/$gl-colCount);

// calculate and store nth portions for grid by columns
$gl-colPortions: (
  0: 0
);
@for $i from 1 through $gl-colCount {
  $gl-colPortions: map-merge($gl-colPortions, ($i: ($gl-colUnit*$i)));
}

// calculate and store nth fractions for grid by number
$gl-colFractions: (
  0: 0 // Avoid division by zero if $i would start at 0
);
@for $i from 1 through $gl-colCount {
  $fraction: 1 / $i;
  $gl-colFractions: map-merge($gl-colFractions, ($fraction: $fraction * 100%));
}