JSFiddle - React, Tailwind, and code Playground

JavaScript

$(document).ready(function(){
    var x,t1,t2,tfinal;

    t1 = performance.now();

    for(x=0; x<10; x++)
    {
    	calculate();
    }

    t2 = performance.now();
    tfinal = (t2 - t1) / 1000;
    console.log("Execution time: ",tfinal," seconds");
});

function calculate(){
	var a,b,c,d,e,f,g,h,i,j,total;
   
	do {
		a=Math.floor((Math.random() * 9) + 1);
	    b=Math.floor((Math.random() * 9) + 1);
	    c=Math.floor((Math.random() * 9) + 1);
	    d=Math.floor((Math.random() * 9) + 1);
	    e=Math.floor((Math.random() * 9) + 1);
	    f=Math.floor((Math.random() * 9) + 1);
	    g=Math.floor((Math.random() * 9) + 1);
	    h=Math.floor((Math.random() * 9) + 1);
	    i=Math.floor((Math.random() * 9) + 1);
	    j=Math.floor((Math.random() * 9) + 1);
	    total=a+13*b/c+d+12*e-f-11+g*i/j-10;
	}
	while (total!=66);
	

	console.log(""+total+"="+a+"+13*"+b+"/"+c+"+"+d+"+12*"+e+"-"+f+"-11+"+g+"*"+i+"/"+j+"-10");
}