In class this week I have been asking students to discuss what is the greatest invention ever and was taken aback to receive the answer "meth" from a student who I assumed had been watching Breaking Bad. Only after several repeats did I realise he meant "math". My confusion was probably caused by the fact that no one from the UK would ever call it "math", only "maths", but I was relieved when I finally understood him.
Incidentally I am still philosophically unsure of whether mathematics counts as an invention or a discovery.