There is an amusing debate in the NYT comments section. The first commenter noted that the question about rectangle area mentioned in the article is not difficult. Others disagreed. My eldest son, a rising 4th grader, got it in a minute. The problem "was taken from the American Mathematics Competitions, a contest series known for its difficulty." I assume it was AMC 8, which is open to students in grades 8 and under. I am planning to have my son take the AMC 8 next year (it is next given on Nov. 15 2011). The local middle school participates in the contest.
