Calculaors for School

I'm a high school student, so I know what a student needs. I used to think that I will not need a calculator since I love to do math in my head. I used the cheap one dollar ones because it's small and portable. Even when my teachers told me I needed a scientific calculator I refused. Without a calculator, I could still do my math homework. Not to brag or anything, but I consider myself a pretty good at math. I was doing pretty good until 9th grade. We had to do sines and cosines and powers. Now, I needed a calculator. I bought my first scientific. At first, I did not know how to use it because it had so many buttons and functions. After awhile, I got used to it and started to rely on it more. Now, I use it all the time when doing my math homework. It is so convenient. I will stick with this one for quite awhile until I desperate need a graphing calculator.