A row machine mixin that uses css calc to ease your rowing

rowMachineCalc

@mixin rowMachineCalc($numPerRow, $margin) {
  @include clearfix();
  display: block;
  > * {
    width: calc(#{(100% / $numPerRow)} - #{(($numPerRow - 1) * $margin)/$numPerRow});
    float: left;
    &:nth-child(n) {
      margin-bottom: $margin;
      margin-right: $margin;
    }
    &:nth-child(#{$numPerRow}n) {
      margin-right: 0;
    }
  }
}