Research shows smart study beats long study for math formulas. Retrieval practice and spaced repetition are key. Quizzing helps more than re-reading. Spacing out reviews improves retention. Mixing ...

The four stamps, issued by China Post, each depicts pi the mathematical constant, the Pythagorean theorem, Euler's formula and Mobius strip. [Photo by Jiang Dong/China Daily] They are enthralled by ...