Practice on timers and working with the DOM in JavaScript

Let us have an input:

<input id="elem" value="1">

Let's make a timer that every second increments the value of the value attribute of our input by one:

let elem = document.querySelector('#elem'); setInterval(function() { elem.value = Number(elem.value) + 1; }, 1000);

Explain why the Number function is used in the above code. What happens if you don't write this function in this code?

Let the input in the value attribute initially contain the number 10. Start a timer that will decrease this number by one every second.

Modify the previous task so that as soon as the content of the input becomes zero, the timer stops running.