Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.3.0.rc.5)
// Compass (v1.0.0.alpha.18)
// ----

@mixin columnize ( $width, $end: 4 ) {
  @for $i from 2 through $end {
    @media ( min-width: $width * $i ) {
      width: 100% / $i;
    }
  } 
}

.foo {
  @include columnize( 200px, 6 );
}

SassMeister-output.css

@media (min-width: 400px) {
  .foo {
    width: 50%;
  }
}
@media (min-width: 600px) {
  .foo {
    width: 33.33333%;
  }
}
@media (min-width: 800px) {
  .foo {
    width: 25%;
  }
}
@media (min-width: 1000px) {
  .foo {
    width: 20%;
  }
}
@media (min-width: 1200px) {
  .foo {
    width: 16.66667%;
  }
}