The calc is extremly useful and easy to use TI-84 PLUS. During my high school career this calc is all i used and now in college i am using it and i prefer it over the 89. It actually sucks that i have to learn the 89 because it is not as awesome. The TI 84 PLUS is not only easy to use, but the buttons are big so that you can see where everything is and you if you use it long enough then you are for sure able to memorize everything. The calc is important for high school because you are allowed to use it on the ACT and on AP exams.