exam_calculate vs Long division + Multiplication Usage & Stats

This is a calculator that allows you to check long multiplication and division calculations, designed to make it easy for supervisors, such as instructors, to identify areas of calculation errors. [Main Features] 1. Pressing the "=" button switches to long multiplication and division mode, displaying the calculation in long form. 2. Division can be calculated to any decimal place by pressing the arrow button to change the settings. 3. Clicking on the "=" button or calculation result display area hides the long multiplication and division screen, and it can be used as a regular calculator (allowing continuous calculations). 4. Clicking on the calculation result screen displays the history of previous calculation results. Students should avoid using this calculator unless they can't find the location of calculation errors on their own (it will decrease their calculation ability).