JSFiddle - React, Tailwind, and code Playground

HTML

<div id="dBlock">

</div>

JavaScript

jQuery( document).delegate( "#dCalc input[type='button']", "click",
    function(e){
    var inputId = this.id;
        console.log( inputId );
    }
);

jQuery( document ).ready( function(){
    
    jQuery( "#dBlock").html('<div id="dCalc">\
  <input id="firstNumber" type="text" maxlength="3" />\
  <input id="secondNumber" type="text" maxlength="3" />\
  <input id="btn1" type="button" value="Add" />\
  <input id="btn2" type="button" value="Subtract" />\
  <input id="btn3" type="button" value="Multiply" />\
  <input id="btn4" type="button" value="Divide" />\
 </div>');
    
});