JSFiddle - React, Tailwind, and code Playground

HTML

<button id="btn" onclick="start()">Press the button</button><br/>
    <h1 id="show1"></h1>
    <h1 id="show2"></h1>
    <h1 id="show3"></h1>
    <h1 id="show4"></h1>
    <h1 id="show5"></h1>

JavaScript

function start(){
            var num1 = Math.random();
            var num2 = Math.random();
            var num3 = Math.random();
            var num4 = Math.random();
            var num5 = Math.random();
            var num11 = num1.toFixed(3);
            alert(num1);
            var num22 = num2.toFixed(3);
            var num33 = num3.toFixed(3);
            var num44 = num4.toFixed(3);
            var num55 = num5.toFixed(3);
            /*var num111 = (num11 * 50);
            var num222 = (num22 * 50);
            var num333 = (num33 * 50);
            var num444 = (num44 * 50);
            var num555 = (num55 * 50);
            /* ---------------------------------------------- 
            var num111 = (num11) += 30;
            var num222 = (num22) += 30;
            var num333 = (num33) += 30;
            var num444 = (num44) += 30;
            var num555 = (num55) += 30;*/
           document.getElementById("show1").innerHTML=num11 + '×' + '50' +    '+' + '30' + '=' + Math.round(num11*50+30);
            document.getElementById("show2").innerHTML=num22 + '×' + '50' + '+' + '30' + '=' + Math.round(num22*50+30);
            document.getElementById("show3").innerHTML=num33 + '×' + '50' + '+' + '30' + '=' + Math.round(num33*50+30);
            document.getElementById("show4").innerHTML=num44 + '×' + '50' + '+' + '30' + '=' + Math.round(num44*50+30);
            document.getElementById("show5").innerHTML=num55 + '×' + '50' + '+' + '30' + '=' + Math.round(num55*50+30);
        }