const millisToMinutesAndSeconds = (millis) => {
var minutes = Math.floor(millis / 60000);
var seconds = ((millis % 60000) / 1000).toFixed(0);
//ES6 interpolated literals/template literals
//If seconds is less than 10 put a zero in front.
return `${minutes}:${(seconds < 10 ? "0" : "")}${seconds}`;
}