Mechanical Minds - S2.E5

Computers - digital computers, electrical computers, wind, steam and sun computers. Computers that talk and computers that draw. Plus an invitation to knock about the oldest computers known to man. Meanwhile - Think of a Number: spot this one without the aid of a computer! What arithmetical symbol can you or a computer use between 2 and 3 to make a number larger than 2 but less than 3 ?