Sir

I shared S. P. Diggle and colleagues' Letter 'Cooperation and conflict in quorum-sensing bacterial populations' (Nature 450, 411–414; 2007) with my ninth-grade mathematics students, because I was fascinated by the bacterial communication system known as 'quorum sensing' — as well as by exploitation in the prokaryotic realm.

I explained that even bacteria know how to assess their own numbers, which enables them to coordinate their behaviour and survival. The importance of mathematics and evidence of cheating in the world of bacteria could be compared with the case of a student who exploits the cooperative calculation of an answer to a specific algebraic problem set during, and resulting from, group work.

The discussion generated an opportunity for the students to identify certain similarities between bacterial behaviour and the dynamics of more complex organisms such as humans, and to show that mathematics is as ubiquitous as bacteria.

I have received positive feedback from parents encouraging the continued integration in the classroom of mathematics with other scientific disciplines and real-world scenarios. Thanks to the authors and to Nature for publishing a paper understandable to the average reader.