JSFiddle - React, Tailwind, and code Playground

HTML

<input data-val-number="" type="text" />

JavaScript

$('body').on('blur','input[data-val-number]',function(){
 if( this.value[0] == "." ){
  this.value = "0" + this.value; 
  //$(this).valid();//must be used with jquery.validate included
 }
});