<div class="grid">
</div>

.item {
  height: 50px;
  border: 1px solid red;
}
.grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
}

const grid = document.querySelector('.grid');
for (let i = 15; i > 0; i--) {
  
  grid.innerHTML += '<div class="item">'+i+'</div>';
  
}