<div style="height:50rem; width:100%; margin: auto;">
<div style="height:50rem; width:20%; margin-left:4%; margin-right:0%; float:left; background-color: black;"></div>
<div style="height:50rem; width:20%; margin-left:4%; margin-right:0%; float:left; background-color: black;"></div>
<div style="height:50rem; width:20%; margin-left:4%; margin-right:0%; float:left; background-color: black;"></div>
<div style="height:50rem; width:20%; margin-left:4%; margin-right:0%; float:left; background-color: black;"></div>
</div>
_x000D_
margin-right isn't needed though.