> Japan is not in the Occident. And I don't know the Japanese education system. I know that the Chinese high-school-equivalent mathematics curriculum is slight

> Japan is not in the Occident. And I don't know the Japanese education system. I know that the Chinese high-school-equivalent mathematics curriculum is slightly different to what I've seen from English and French and German (and American) schools, so the current Japanese system might be different as well. (Though, the Chinese system also has the issues I've described.) > By the way, the "solution" cited in the article is "divide the blue radius by 3", with no proof, Many results in mathematics are published without proof, and are still considered significant. Heck, Euclid's Elements, which is known for its generally rigorous attitude, omits full proofs of several results. > Also, the article incorrectly transcribed the problem from the photograph into the computer diagram, Arguable. I'd say they just chose different values for the free parameters. > and the original woodcut doesn't even show an eclipse You're right. But it does show a sketched ellipse – at least, that's similar to how I drew them before I became familiar with computer-rendered examples. The insistence on geometry diagrams being to-scale is a fairly recent phenomenon: generally, owing to the difficulty of producing to-scale diagrams, the attitude has been "don't trust the diagram", and the focus when creating a diagram is making sure that intersection points are obvious. Look into the modern tradition of curve sketching. > and the problem doesn't make a whole lot of sense (the red and white circles are completely irrelevant to the problem) They're not irrelevant: they constrain the relative positions of everything as the size and position of the blue circle varies. They're not relevant when the blue circle is at its maximum, but that's part of solving the problem. > Finally, the article title is a clickbait lie. The subtitle, “A Historical Look at Japan’s “Wasan” Math”, is much better.