A Finger Trick for Trigonometry (Tanton: Mathematics) @DrJamesTanton

Uploaded February 2011 | Updated September 2026, 3 weeks ago

If we insist that students memorise the values of sine and cosine for the basic angles 0, 30, 45, 60 and 90 degrees, then here's a cute little trick for doing so using the fingers on your hand. (Notice: This all goes against my principles of as a mathematician - memorisation is joyless! But I do admit this finger trick is cute!)

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$Egyptian Fractiions and Fibonaccis Greedy Algorithm (TANTON Mathematics) The Egyptians of ancient times were very practical people and the curious way they represented fractions reflects this! In this - brief - video we explain the Egyptians rationale and show how some 2000 years later Fibonacci settled the question as to whether every fraction can indeed be written the Egyptian way. (Did the Egyptians themselves ever worry about this?)$