Completely different numbers
Hello!!! I need the help of experienced and not very arduino players. I am doing a project. Money box. The project consists of a tweeter, 4x4 matrix keyboard, LCD 1602 I2C, as well as Arduino UNO. I've already done everything except balance. When I enter the number to be added, then I have a completely different number in the balance! Help me please. I am writing here for the first time, so I don’t know the etiquette :)