nikoshot,
не копируйте сообщения целиком, без надобности, есть цитирование.
<!DOCTYPE html>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
<style type="text/css">
.view_hide {
background-color: rgba(0, 255, 255, 1)
}
.sum{
background-color: rgba(255, 0, 255, 1);
}
</style>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script>
$(function() {
let max_view = 4;
$(".options_no_buy").each(function(i, { children }) {
let { length } = $(children).slice(max_view).addClass("view_hide");
length && $(`<div class='sum'>${length}</div>`).appendTo(this)
})
});
</script>
</head>
<body>
<div class="options_no_buy ">
<div class="items">1</div>
<div class="items">2</div>
<div class="items">3</div>
<div class="items">4</div>
<div class="items">5</div>
<div class="items">6</div>
</div>
<div class="options_no_buy ">
<div class="items">1</div>
<div class="items">2</div>
<div class="items">3</div>
<div class="items">4</div>
<div class="items">5</div>
<div class="items">6</div>
<div class="items">7</div>
<div class="items">8</div>
<div class="items">9</div>
</div>
<div class="options_no_buy ">
<div class="items">1</div>
<div class="items">2</div>
<div class="items">3</div>
<div class="items">4</div>
</div>
</body>
</html>