Purchased this for my son, he is taking some college level math and engineering classes, he was excited to receive it. The problem is the screen is not properly attached to the case of the calculator and had a 1/8' gap. The tough screen protector had to be cut to accommodate the power button. and overall the buttons were hard to press and made for awkward not intuitive calculations. He asked me to returned in and is using his 15 year old TI-89.