JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
    <div class="tenPercent">1</div>
    <div class="tenPercent">2</div>
    <div class="tenPercent">3</div>
    <div class="tenPercent">4</div>
    <div class="tenPercent">5</div>
    <div class="tenPercent">6</div>
    <div class="tenPercent">7</div>
    <div class="tenPercent">8</div>
    <div class="tenPercent">9</div>
    <div class="tenPercent">10</div>
</div>

CSS

.container {
    width: 960px;
    background: red;
    margin: 0 auto;
}
    .container:after {
        display: table;
        content: '';
        clear: both;
        
    }

.tenPercent {
    color: #000;
    float: left;           
    border: 1px solid black;
    width: 10%;

    -webkit-box-sizing: border-box;
       -moz-box-sizing: border-box;
            box-sizing: border-box;
}