Courtesy of BBC

When this science series launched in 1977, Johnny Ball was best known for clowning about on Play School (BBC, 1964-88) and so might have seemed an unlikely factual presenter. Yet he went on to write and front 15 series of this and its many spin-offs.

Think of a Number (BBC, 1977-84) was envisaged as a light-hearted puzzle show, but developed to become, in the days before the phrase 'infotainment' was coined, a genuine factual series, billed as 'a light-hearted exploration of science and number'.

The programme worked as a series of excitable science lectures, with Ball playing to a young audience in a set-up slightly reminiscent of a lecture theatre. On television, every principle needed to be illustrated with an interesting visual hook or trick, so Ball took an approach reminiscent of the lunatic science teacher inviting the class to come out and try out the Van Der Graaf generator - fun to watch but always with some serious ideas behind the terrible jokes. John Bone's basic but clever set hid a myriad of secret doors housing the next prop, and audience members were regularly asked to volunteer to be Johnny's stooge, so avoiding a pedagogical style.

The series ran concurrently with several spin-off formats: Think Again (BBC, 1981-85) mused upon non-science subjects; Think! Backwards (BBC, 1981) discussed number-related topics (despite the title, Think of a Number was rarely about maths); Think! This Way (BBC, 1983) followed points of the compass; Think It ... Do It (BBC, 1986-87) looked at occupations. The original series won many major awards, including an American Emmy nomination, while Ball received an outstanding achievement award from BAFTA for his work on these series.

Alistair McGown

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