Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.3.0.rc.2)
// Compass (v1.0.0.alpha.17)
// ----

    $numbers: ("3": "three", "4": "four");

    @each $number, $i in $numbers {
        .#{$i}-#{$number} {
            /* CSS styles */
        }
    }

SassMeister-output.css

.three-3 {
  /* CSS styles */
}

.four-4 {
  /* CSS styles */
}