Move a div below another div at a certain screen width

Question

I have a mobile website with 4 banners that appear side by side. When I get to a certain screen width, I want 2 of them to drop below the other 2. Part of the problem is that I have used width: 24.96% to obtain the right total width of all 4 divs to fit the body.

CSS

.small_banners .banner_block {
  display: block;
  max-width: 100%;
  height: auto;
  width: 24.96%; }

.small_banners {
  float: left;
  clear: both;
  width: 100%;
  margin: 0 0 15px; }

HTML

<div class="small_banners">
    <div class="banner_block">
      <div>
        Content
      </div>
    </div>
    <div class="banner_block">
      <div>
        2nd piece of content
      </div>
    </div>
    <div class="banner_block">
      <div>
        3rd piece of content
      </div>
    </div>
    <div class="banner_block">
      <div>
        The 4th piece of content
      </div>
    </div>
  </div>

When the screen reaches 958px I want the 3rd and 4th divs to drop below the 1st and 2nd, using a simple media query: @media all and (max-width: 958px) {

Answer 1

this should work.

 @media (max-width: 958px) {
        .small_banners .banner_block{
           width:50% !important;
      }
    }