Obtaining interaction and engagement in large group teaching can be challenging, in particular in STEM subjects where it is essential to be able to efficiently present symbols, equations and formulae. Pingo is a free, cloud based system that provides an excellent way of introducing interaction in large group teaching. It is particularly useful in the Mathematics based subjects mentioned above as it is LaTex compatible, and it is primarily for this reason that it stands out from other similar systems. Such interaction also provides feedback to students and lecturers, and it is a straightforward, but creative way to enhance student engagement. The speaker has tried and tested Pingo on a weekly basis in two Mathematics modules and obtained both high participation rates and very positive feedback. This talk will provide all the information and resources required to start using Pingo along with a live, interactive demonstration.