This Python program defines a class-based interactive calculator that lets users perform four fundamental arithmetic operations: addition, subtraction, multiplication, and division. It provides a user-friendly menu to select operations in a loop and handles invalid inputs with simple validation checks. Once a calculation is completed, users are prompted to perform an additional operation (called ans) on the result of the previous computation, such as multiplying, dividing, adding, or subtracting it by another number. The core logic is built using a class omar, which includes methods for each arithmetic operation. The ans() method provides an extended interactive feature for chaining another computation based on the previous result. The entire program runs in a loop until the user chooses to exit.