I don't have that problem just yet, but the case I use only has one elastic band actually, so it would work until they are REALLY short. At that point, I have heard of super gluing them to the end of your new pencil. If you just use a dot it ends up a very thin line and you can sharpen through it when the time comes. Of course, if the singles come sharpened now too that won't work! Or yeah, pencil extenders.