Posted in Simple math by: admin

5 Comments

27 Mar

TweetJeffrey Samuelson twitted a question to which I am happy to provide an answer, or two. Question Find an integer N such that N(N+1)(2N+1) is NOT divisible by 6. If no such integer exists, prove why. Since the question is about the properties of a product modulo 6, it seems proper to investigate the dependency […]

Posted in Curiosity by: admin

1 Comment

26 Mar

TweetWhen Tennyson wrote The Vision of Sin, Babbage read it. After doing so, it is said he wrote the following extraordinary letter to the poet: "In your otherwise beautiful poem, there is a verse which reads: 'Every moment dies a man, Every moment one is born.' "It must be manifest that, were this true, the […]

Posted in Beautiful curiosity, geometry by: admin

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21 Mar

Tweet (Borrowed from http://www.boingboing.net/2011/03/21/how-to-make-a-hamant.html)

Posted in Beautiful math, How children learn, Simple math by: admin

5 Comments

20 Mar

TweetSimple mathematics may be rather impressive even on an early developmental level. The "1089 prediction" is one of the better known tricks that may be presented to the 3-4 grade audience. David Acheson describes it thus: Think of a three-digit number. Any three-figure number will do, so long as the first and last figures differ […]

Posted in Beautiful math, Curiosity, Education reform, Math in news by: admin

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14 Mar

TweetMarch 14 is practically an official π day. Why is that? March is the fourth month of the widely accepted Gregorian calendar and, not incidentally, π ≈ 3.14. There are dissenting voices that claim July 22 as a more appropriate day for the celebration because 22/7 (≈ 3.14286) is a better approximation to the real […]

Posted in Education reform, Simple math by: admin

4 Comments

08 Mar

TweetI cannot recollect which book it was but I do remember it was a book by a famous mathematician who wrote in Introduction that to write a book is the best way to learn a new topic. I got this memory flash when reading an article in Mathematics Teacher: Our teachers misled us, but we […]

Posted in Beautiful curiosity, Simple math by: admin

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08 Mar

TweetYou have to see it to believe it.

Posted in Algorithms, Arithmetic, Simple math, Teachers at play carnival by: admin

2 Comments

05 Mar

Tweet[mathjax] A decimal integer has the form A divisibility criterion is a procedure, in some sense simpler than straight division, that allows us to determine whether or not number is divisible by another number . For example, is divisible by if and only if the sum of digits is divisible by . For example, is […]