Generated by SassMeister.com.

SassMeister-input-HTML.html

<div>1</div>
<div>2</div> 
<div>3</div> 
<div>4</div> 
<div>5</div> 
<div>6</div>
<div>7</div>
<div>8</div> 
<div>9</div> 
<div>10</div> 
<div>11</div> 
<div>12</div>

SassMeister-input.scss

// ----
// Sass (v3.3.9)
// Compass (v1.0.0.alpha.20)
// Singularity.gs (v1.2.1)
// ----

@import "singularitygs";
* {
  box-sizing: border-box;
}
// Singularity 1.2 Syntax
@include add-grid(12);
@include add-gutter(20px);
@include add-gutter-style('split');

div {
  @include float-span(1);  
  border: 1px solid red;
}

SassMeister-output.css

* {
  box-sizing: border-box;
}

div {
  width: 8.33333%;
  clear: right;
  float: left;
  padding-left: 10px;
  padding-right: 10px;
  border: 1px solid red;
}

SassMeister-rendered.html

<div>1</div>
<div>2</div> 
<div>3</div> 
<div>4</div> 
<div>5</div> 
<div>6</div>
<div>7</div>
<div>8</div> 
<div>9</div> 
<div>10</div> 
<div>11</div> 
<div>12</div>