Up front I have almost no experience with this kind of thing. I'm a computer scientist so I understand logic gates and the like but I know near nothing about electricity.
What I want to do is build a device that has 2 buttons and a series of LEDs. When one of the buttons is pushed the leftmost unlit LED should light up and stay lit. When the other is pushed the leftmost lit LED should unlight. So it can be used to manually keep track of a count of something. I'm estimating that I'd have around 10 round LEDs.
I want it to be battery powered, as opposed to wall-powered. I was thinking about using a disposable 9 volt battery as a source. With typical LEDs that use 20 mA a piece, I found that the minimum current that this device would draw is 200 mA.
I've found a few beginner's guide type things that have counters but they're usually not button controlled or don't use lights and I've never seen one that has a button to go backwards.
Originally I thought this would be fairly easy but the more I research the more I'm getting completely lost.