wasting the batteries? When I do my math hw and have my TI-83 calculator out, I tend to turn it off after I am done with the problem i'm on and a few seconds later I turn it back on. I'm a little paraniod the batteries will run out when I really need them so I've started turning off my calculator every time I'm not using it. I was wondering if in doing so, i'm actually killing the batteries more then if I just left my calculator on 20 mins at a time instead of turning it off and on after every single problem. Any help would be great. Thanks