The grid cells below do not specify any widths, they just naturally space themselves equally and expand to fit the entire row. They’re also equal height by default.
<div class="grid">
<div class="grid-cell"> 1/2 </div>
<div class="grid-cell"> 1/2 </div>
</div>
<div class="grid">
<div class="grid-cell"> 1/3 </div>
<div class="grid-cell"> 1/3 </div>
<div class="grid-cell"> 1/3 </div>
</div>
<div class="grid">
<div class="grid-cell"> 1/4 </div>
<div class="grid-cell"> 1/4 </div>
<div class="grid-cell"> 1/4 </div>
<div class="grid-cell"> 1/4 </div>
</div>
<div class="grid">
<div class="grid-cell"> 1/5 </div>
<div class="grid-cell"> 1/5 </div>
<div class="grid-cell"> 1/5 </div>
<div class="grid-cell"> 1/5 </div>
<div class="grid-cell"> 1/5 </div>
</div>