Substitutes are not so easy to find. After using an app on my phone, and then my desktop computer, to try and do homework that included lots of numerical calcul

Substitutes are not so easy to find. After using an app on my phone, and then my desktop computer, to try and do homework that included lots of numerical calculations, I quickly reverted to the hard-keys of my calculator with which I was working faster and more accurately. I've personally found the key layout of the calculator to be a lot more efficient than a desktop computer's, and the touchscreens to be flexible but error-prone.