This paper describes the theoretical motivation and practical mounting of a workshop in which participants could experience and reflect on the value of theatre in bringing mathematical ideas and history to life in the classroom. All participants were involved in the production and enactment of a short pre-scripted play, requiring minimal preparation. This was followed by discussion, small group work, and feedback. The play, given in full below, evokes the cultural context within which a Chinese mathematical practitioner may have operated about two millennia ago, and suggests how the Rule of Excess and Deficiency for equation solving could have been inspired and recorded, as Problem 17 in Chapter 7 of the Jiu zhang suan shu (The Nine Chapters). Nine representative scribes/mathematicians from different cultures make cameo appearances, giving the names for ‘the unknown’ used in equation-solving in their time. The dialogue is accessible and lively, laced with humour and emotions, portraying the excitement of mathematics-making. Based upon primary sources, the play can inspire interest in authentic contextual history of algebra while motivating the learning of algebra.