The calculator is useful for my basic needs in applying the calcs for resistance and voltage used in lighting and switching circuits. 4 basic electronics use, I am not designing anything complex. It works well and saves on pencil and post its. I think the TI-30x is capable of a lot more and recommend it over some of my graphing ones, less buttons and multiple functions which require a lot more focus. I am using this since the second day and really like the investment. I recommend it for users that need the visual representations, carpenters, mechanics and even some plummers may find applications for the TI=30x.