From time to time, I try to speak or write about mathematics for general (non-mathematical) audiences. If you've done this, you know it's pretty hard -- in large part because it's hard to know what people know, despite my best attempts to find out.

Enter Google Surveys. For a pretty reasonable fee, it turns out anyone can run a survey through Google; the respondents are randomly selected and reweighted by demographics (age, gender, location). So I decided to find out: What percentage of Americans over the age of 18 know what a prime number is? What about an even number? I also tried to design the questions so they tested a bit more than basic knowledge; for example, I wanted to know whether the respondents knew that zero is even (a surprisingly controversial topic).

Methodology

Here are the two surveys I ran, as they would appear to respondents. Each survey received about 250 responses from randomly selected Americans over the age of 18. (And cost me a well-spent $25.)

Even numbers: