If you want to solve using a calculator, it is best to press C/AC first, then type in the numbers and symbols. I made a normal calculator that you can use for math calculations. It consists of 10 numbers, 20 math signs, C/AC , and an Answer button (in fact, some calculators don't have that). If you clicked a math sign before inserting the initial number, it will be just 0. Warning: Always choose a number before pressing one of the advanced signs at the top. Forget what your previous answer was? If so, click on Scratch Cat.
