Practice on timers and working with the DOM in JavaScript

Let us have an input:

html<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:

javascriptlet elem = document.querySelector('#elem');

setInterval(function() {
  elem.value = Number(elem.value) + 1;
}, 1000);

Задание 1

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

Задание 2

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

Задание 3

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