Generated by SassMeister.com.

SassMeister-input-HTML.html

<div class='container'>
  <div class='block'> </div>
  <div class='block'> </div>
  <div class='block'> </div>
  <div class='block'> </div>
</div>

SassMeister-input.scss

// ----
// Sass (v3.4.12)
// Compass (v1.0.3)
// Singularity.gs (v1.5.1)
// ----

@import "singularitygs";
@include add-grid(14);

.container {
  background-color: lightpink;
  height: 100px;
  width: 100%;
}

.block {
  @include grid-span(3, 2, $output-style: 'float');
  background-color: lightgrey;
  height: 25px;
}

.block:first-of-type {
  margin-left: grid-span(1, 1);
}

SassMeister-output.css

.container {
  background-color: lightpink;
  height: 100px;
  width: 100%;
}

.block {
  width: 20.28986%;
  clear: right;
  float: left;
  margin-right: 1.44928%;
  background-color: lightgrey;
  height: 25px;
}

.block:first-of-type {
  margin-left: 7.24638%;
}

SassMeister-rendered.html

<div class='container'>
  <div class='block'> </div>
  <div class='block'> </div>
  <div class='block'> </div>
  <div class='block'> </div>
</div>