Grid halves

50%
50%
50%
50%
50%
Show/hide markup 
<div class="grid halves">
    <div class="column-demo">50%</div>
    <div class="column-demo">50%</div>
    <div class="column-demo">50%</div>
    <div class="column-demo">50%</div>
    <div class="column-demo">50%</div>
</div>