Floating a JS made div

Sup all?
Pretty new to JS here so forgive me if this is a really dumb question but I’m having no luck finding an answer. I am making some divs with js and the short of it is I want em to float to the left.

I’ve tried this :

document.getElementById(“tile” + i).style.float = ‘left’;

and

newDiv.style.float = ‘left’;

but neither have worked. Can anyone point out what I’m doing wrong?
Thanks