L need help with something in my program

it goes in a loop but l don’t know how to get it to add the same variable over and over again l don’t know if this sounds stupid or not but l looked all online and couldn’t find anything my lines of code are below while True: number = input("please input first number you’d like: ") try: first_number = float(number) except ValueError: print("that's not a vaild number ") continue finally: stop = input("would you like the equation to stop ") if stop == "ye...