Hi there. This project was done using openCv and cvzone libraries. The idea is: you stand in front of the camera of your pc, and when you raise your hand up in front of the camera, you'll see landmarks on your hand and you'll notice two big landmarks on your index finger and thumb. When you move your hand at the calculator and close those fingers (index and thumb), you'll notice clicking on the button and this button will be printed on the display of the calculator. You can write the equation, then click '=' and you'll see the result on the display. When you click on the 'c' button on your keyboard, the calculator will clear the display. When you click on the 'x' button on your keyboard, you'll close the calculator When you remove the hashtag from the command line of the 'd' button in the code of this program, and click on the 'd' button on your keyboard, you'll remove the last thing you write. You can see the video here. Thank you.