To do this you will reset the calculator. If this happens, you'll want to be able to get the calculator back to its 'normal' mode. (Or you might loan the calculator to a friend who changes the settings). Your calculator has a lot of settings that you might never use (things like FIXED notation, or RADIAN mode), but if you're not paying attention to what you're doing, you could accidentally get your calculator in different settings than you want. For example, to get the % function, press 2nd, and then the open parenthesis key. In general, press the 2nd button any time you want to use alternate meaning of a button. How do you use the OFF feature? Press the button in the upper left corner labeled 2nd, then press the ON button. This means that the ON button is used for two purposes: to turn the calculator on and to turn it off. Notice that above the ON button, there is smaller text that says OFF. This is easy in the lower left corner there is a button labeled ON. One of the first things you'll need to do is turn your calculator on. The difference between these calculators is that the IIS is Solar Powered, and the IIB is Battery Powered. You should have in front of you either a TI-30X IIS or a TI-30X IIB.