I usually refer people to read What Is Mathematics For? published on the Notices of AMS. http://www.ams.org/notices/201005/rtx100500608p.pdf http://www.ams.org/

I usually refer people to read What Is Mathematics For? published on the Notices of AMS. http://www.ams.org/notices/201005/rtx100500608p.pdf http://www.ams.org/notices/201005/rtx100500608p.pdf In short, most people will not use math more advanced than arithmetic, unless they are mathematicians/physicists.