How do you position HTML Elements next to eachother? [on hold]

I'm trying to position plus and minus buttons at either end of a slider. The slider is a div and the plus and minus buttons are img elements. I'd prefer to use CSS, but if this can be done in HTML or JavaScript that's fine too.

Currently I'm simply hardcoding the position of the buttons next to the slider, but of course this leads to issues when the elements above the slider grow and push the slider down.