Published on *Natural History Magazine* (http://nhmag.com)

For an older generation, the word arithmetic conjures up an image of a grocer adding a column of numbers on a brown paper bag. For a much younger generation, it raises the question: What’s arithmetic? That question may be symptomatic of why the high school graduating class of 2011 in the United States ranked thirty-second in the world in math proficiency (www.schoollibraryjournal.com/slj/home/891733-312/u.s._students_rank_32_in.csp).

Concern about America’s math deficiency has prompted Neil deGrasse Tyson to ask, “Is the twentieth century’s global technological leader becoming an idiocracy?” An excerpt from his book *Space Chronicles: Facing the Ultimate Frontier*, in which he raises that question, is on our website: www.nhmag.com/perspectives/012148/by-the-numbers. Or, you can watch Tyson deliver the speech on which that excerpt is based at www.haydenplanetarium.org/tyson/watch/2008/04/12/24th-nationalspace-symposium-keynote.

With the spotlight on ’rithmetic and what the U.S., collectively, may or may not know about it, you may have a renewed interest in the subject, starting with the history of numbers. A generous survey is available from the School of Mathematics and Science of Scotland’s University of St. Andrews (see www-history.mcs.

st-and.ac.uk/Indexes/HistoryTopics.html). If you want to practice your math skills, “from addition to calculus and everything in between,” there is no better site than www.khanacademy.org. International Ataturk-Alatoo University offers free online courses in applied mathematics (see ocs.iaau.edu.kg/moodle), and MIT OpenCourseWare (OCW) has free access to the lecture notes, exams, and videos of “almost all the undergraduate and graduate subjects taught at MIT.” The URL for mathematics is ocw.mit.edu/courses/mathematics.