JSFiddle - React, Tailwind, and code Playground

HTML

<div class="wrapper">

						<div class="item-course item-39">thirtynine</div>
						<div class="item-course item-28">twentyeight</div>
						<div class="item-course item-52">fiftytwo</div>
						<div class="item-course item-45">fourtyfive</div>
            <div class="item-course item-26">twentysix</div>
            <div class="item-course item-51">fiftyone</div>
                        
     </div>

JavaScript

jQuery(document).ready(function(){
	
   	var $wrapper = $('.choose-course-3-wrapper');

	$wrapper.find('.item-course').sort(function(a, b) {
		
		var aclassStr = a.attr('class'),
    		asortNum = classStr.substr( classStr.lastIndexOf('-') + 1);
		var bclassStr = a.attr('class'),
    		bsortNum = classStr.substr( classStr.lastIndexOf('-') + 1);
	
		return +asortNum - +bsortNum;
	})
	.appendTo($wrapper);
 
} );