Turns on when batteries are put in - 1 9 volt (not included) and 2 G13 today sold as AG13.  I left the 2 in and am giving 8 more (I just bought the 10 on Amazon). My dad passed away in Feb 2024 and I found this among his possessions. Calculator doesn't work. I couldn't figure out how the cassette worked when turned on but it made noise when pressing buttons. My only cassette tape that my dad had with it was very old and torn.