How to only add something to html with js

Question

I made a program that calculates the fibbonacci series until 4000 is reached, but i cant add in the span i made, i only can replace the text
https://code.sololearn.com/W9sIJJlLidVq/?ref=app

Answer 1

https://code.sololearn.com/WepAcBz38J4F/#html

Answer 2

document.getElementById("body").innerHTML = document.getElementById("body").innerHTML + " " + number;

You need to include the old html with your new one.

Answer 3

and how do i make a constantly repeating if loop like this:
function(){
//function
goto function()
}
is this possible?