Arithmetic, Population, and Energy by Dr. Albert A. Bartlett
I've posted some links because I was curious about your opinion; this one I think is important, clear, and convincing. Unfortunately, I don't see a good way of summarizing it - wonderingmind42, who uploaded it, did a pretty iffy job with the title, in my book - but I'll try: the lecture is about the nature of steady percentage growth (e.g. 7%/year) and the policy implications that come out of the arithmetic. You don't need anything more than multiplication and division to follow the reasoning - the most difficult calculation is for the doubling time, and that goes
years to double = 70 / % growth per year
which is accurate to one part in twenty for any growth rate up to 12%/year.
I think it's worth at least 90 minutes of your time - 75 minutes is a steal at the price.