Season
- Season 5 1984-01-04
- Season 4 1982-09-15
- Season 3 1980-09-10
- Season 2 1979-09-12
- Season 1 1978-04-12
- Season 0 1977-04-02
Think of a Number Season 1 Episode 1
A light-hearted exploration of maths and science, presented by Johnny Ball.
