Thanks! :) We were really thrilled to post the problem. Our rope question from expii.com/solve is a multi-layered math puzzle. If you haven't seen it before, t

Thanks! :) We were really thrilled to post the problem. Our rope question from expii.com/solve is a multi-layered math puzzle. If you haven't seen it before, the answer is often quite surprising: a human can walk under the circle even though the 710 inches of extra length are shared over the whole earth's circumference. Basic human intuition produces the most common answers, which are the bacteria or the ladybug. This helps to illustrate the purpose of math: to help us reason to determine the truth when basic intuition fails. If basic intuition were always right, then we wouldn't need math! If you had seen the puzzle before though, you would already know that the rope lifts high, because it lifts by 710/(2*pi) inches, which is 113.0000095... taking us to the second layer of math embedded deeper in the problem. That is remarkably close to a whole number, which is surprising because pi is an irrational number. This means that pi is very close to 355/113, which brings us to the topic of Continued Fraction representations of irrational numbers, and amazing rational approximations of pi: https://en.wikipedia.org/wiki/Mil%C3%BC https://en.wikipedia.org/wiki/Mil%C3%BC So, this problem hits at both basic and advanced levels. :) There are many interesting ways to teach math through multi-layered puzzles which have something for everyone, no matter where you are in the experience spectrum. Our goal is to provide these for free, disseminated over the Internet. :)