Generated by SassMeister.com.

SassMeister-input.scss

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

@for $d from 1 to 10 {
  %color-#{$d} {
    color: scale(red, 10% * $d);
  }
}

@for $d from 1 to 10 {
  %text-#{$d} {
    font-size: 1px * $d;
  }
}

@for $d from 1 to 10 {
  %border-#{$d} {
    border: 1px solid scale(blue, 10% * $d);
  }
}

@for $d from 1 through 3 {
  .foo-#{$d} {
    @extend %color-#{$d};
    @extend %text-#{$d};
    @extend %border-#{$d};
  }
}

SassMeister-output.css

.foo-1 {
  color: scale(red, 10%);
}

.foo-2 {
  color: scale(red, 20%);
}

.foo-3 {
  color: scale(red, 30%);
}

.foo-1 {
  font-size: 1px;
}

.foo-2 {
  font-size: 2px;
}

.foo-3 {
  font-size: 3px;
}

.foo-1 {
  border: 1px solid scale(blue, 10%);
}

.foo-2 {
  border: 1px solid scale(blue, 20%);
}

.foo-3 {
  border: 1px solid scale(blue, 30%);
}