sistema hexadecimal https://www.youtube.com/watch?v=TVI2Vxd7HTY principio basico https://www.youtube.com/watch?v=OjN40z7kN0I suma https://www.youtube.com/watch?v=HaKQsJcfjYM resta https://www.youtube.com/watch?v=S4ux71Lgc4Y multiplicacion https://www.youtube.com/watch?v=FNCsWgFWWWU division