Posted in Early math, Education reform, Problem solving, Proofs Without Words, Puzzles by: admin

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03 May

In passing, I totally disagree with Tanya's thesis that "People who think make better decisions, whether they want to buy a house or vote for a president." That's factually wrong. This would be rather presumptuous to assume that the ones who disagree with one's choice of a president give their vote thoughtlessly. I am certain Tanya did not mean that.

Posted in Books to read, Puzzles, Uncategorized by: admin

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23 Feb

Tweet The book in fact has a longer title: The Population Explosion and Other Mathematical Puzzles. The title warrants an observation. I once wrote of the difference in attitude of mathematicians and puzzlists to solving problems. While, for a puzzlist, solving a problem is a goal in itself, for a mathematician it may serve as […]

Posted in Algebra, Books to read, geometry, math fun, Puzzles, Uncategorized by: admin

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01 May

As you may surmise, the path will behave - if I may say so - in a more rational way. Given the incommensurate dimensions of the box it was rational to expect an endless path. This is what you get on the second attempt. But there remains a question to ponder: Why was the first path so short? Jim Henle leaves to his readers to find the answer.

Posted in Arithmetic, Books to read, Early math, Math activities, Puzzles, Uncategorized by: admin

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18 Jan

In his last book *Mathematical Allurments* (*Matematicheskie Zavlekalki*), published posthumously in 2000, he tells a story of a 7th grade girl who got tempted to solve that problem and found a solution, too. She informed Kordemsky that her solution was different from the one in the book. Kordemsky encouraged her to look further, for other solutions. Several of her classmates get involved in the search that eventually produced more than 120 solutions. I can imagine Kordemsky's delight in seeing his efforts at attracting young minds to mathematics being born fruit. The kids even came up with something unexpected: many of the numbers they came up lead to other solutions when some pairs of their digits get swapped.

Posted in A must read, Puzzles, Simple math by: admin

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01 Feb

The country of FarAwaynia is composed of several states and also has several political parties. Once, a group of FarAwaynian politicians got together for a dinner. It is known that the group contained people from at least to different states and from at least two different parties. Prove that there were two politicians at the dinner that represented different states and belonged to different parties.

Posted in Books to read, Puzzles by: admin

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10 Sep

On the whole, this is a lovely book that both extends and complements the previous four. One does not have to love all of the included puzzles, but their number and variety practically guarantees that there are many that you will enjoy.

Posted in Books to read, Puzzles by: admin

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20 Jul

The book contains a variety of puzzles, some simple, others more complicated, none boring. A few have frustrated my efforts to solve them, while the supplied solution showed nonconformist ways in which the Grabarchuk family's cumulative brain works

Posted in Curiosity, Puzzles, Simple math by: admin

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12 Jul

I posed the problem to my (future) 9th grader son whose math teacher I am not happy with. It seems to me that what he does is mostly memorizing formulas and putting in numbers to get numeric results. But the boy proved to still have his wits about him. Without batting an eyelid he gave his answer: "It's simple. It is faster to start moving right away. There is no advantage in losing any time at the outset."

Posted in Books to read, Puzzles by: admin

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10 Jul

I got an impression that on receiving my explanation she immediately purchased the book. I saw that she punched the keys on her tablet and then got engrossed into what she got on it. I may have been wrong about that, but there was no doubt my boy was happy to while away half an hour with Grabarchuk's book.

Posted in Books to read, Puzzles by: admin

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01 Jul

I can't know how the Grabarchuk brothers and their father cooperate in creation of such an enormous variety of puzzles. What I do know is that their puzzles provide hours of happy family experience.