Here's a question that can be answered with a little knowledge of mathematics and history, and some common sense.

Why do "normal" clocks always turn in the direction we are used to, and not in the opposite direction?

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Musings on doing and teaching mathematics, book reviews, math problems. Information about my math education business, Cambridge Math Learning.

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## Elementary Math Problems

## Advanced Math Problems

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From time to time I will post an elementary mathematics problem which I hope readers may enjoy. "Elementary" to me means that the problem does not require any specialized mathematical knowledge beyond high-school mathematics to solve. Some of these elementary problems will be very simple, others will require a great deal of cleverness. Elementary math problems will be denoted by the letter E followed by the problem number.

I will sometimes post a link to a solution. If I haven't yet posted a link, you may send me your answer and if it is correct I will credit you on the blog. To send answers, please mailto: peterash3@gmail.com.

Thanks,

Peter

I will sometimes post a link to a solution. If I haven't yet posted a link, you may send me your answer and if it is correct I will credit you on the blog. To send answers, please mailto: peterash3@gmail.com.

Thanks,

Peter

From time to time post problems that are somewhat more advanced than those in the Elementary Math Problems. These problems will require a knowledge of some college-level mathematics, either for their statement or for the solution that I know. Advanced math problems will be denoted by the letter A followed by the problem number.

I will sometimes post a link to a solution. If I haven't yet posted a link, you may send me your answer and if it is correct I will credit you on the blog. To send answers, please mailto: peterash3@gmail.com.

I will sometimes post a link to a solution. If I haven't yet posted a link, you may send me your answer and if it is correct I will credit you on the blog. To send answers, please mailto: peterash3@gmail.com.

Here are some recent reviews on mathematics, learning theory, education, and related technology:

The Number Sense: How the Mind Creates Mathematics by Stanislaus Dehaene, Oxford University Press 1997

Three Books on the Riemann Hypothesis

The King of Infinite Space: Donald Coxeter, the Man Who Saved Geometry by Siobhan Roberts, Walker and Company, 2006

The Poincare Conjecture: In Search of the Shape of the Universe, Donal O'Shea, Walker & Company, 2007

Where Mathematics Comes From: How the Embodied Mind Brings Mathematics into Being, George Lakoff and Rafael E. Nunez, Basic Books, 2000.

The Number Sense: How the Mind Creates Mathematics by Stanislaus Dehaene, Oxford University Press 1997

Three Books on the Riemann Hypothesis

The King of Infinite Space: Donald Coxeter, the Man Who Saved Geometry by Siobhan Roberts, Walker and Company, 2006

The Poincare Conjecture: In Search of the Shape of the Universe, Donal O'Shea, Walker & Company, 2007

Where Mathematics Comes From: How the Embodied Mind Brings Mathematics into Being, George Lakoff and Rafael E. Nunez, Basic Books, 2000.

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## 2 comments:

Is it because clock was designed to measure time difference (elapsed) and by virtue that time is spent (lost and not gained should be a negative and conventionally anti clock wise measure of angle is negative, it justify the movement of clock needles?

Sorry I missed seeing this. I can't follow your argument. My reason is that the first clocks were designed to imitate sundials. In the northern hemisphere (where clocks were developed), the shadow of the gnomon rotates in the direction we call clockwise.

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