D Battery Holder

so what do I do when I need a D cell or a C cell and all I have is more common double a let me show you obviously these batteries are all different sizes and you can't just plug this double-a cell in the place of these D cells or even these C cells so let's take a device right here that I pulled these two dead D cells out of these are goners there's no juice left can't just take two doublea's and jam them in there and expect them to work or even a bad seal to hand jam those in there and expect them to work but there's a quick and easy hack if you want to call it so I'm going to take a piece of cardboard that actually bends so I can roll it up you don't want one that bends the other way cardboard bends easier one within the other and it's going to be just a little bit shorter and I'm going to take my two batteries and I'm going to make so I can insert these in the middle I'm gonna have t