I’m hosting Carnival of Mathematics #99
I'll be hosting the next Carnival of Mathematics. Please check out this URL to learn more about the carnival, to vist past carnivals, or to submit your blog article for #99. Submission deadline is 6/1/13.
81st Carnival of Mathematics
Welcome to the September 2, 2011 edition of carnival of mathematics.
This is the 81st edition. In the tradition of the Carnival of Mathematics, we provide trivia on the number of the edition.
- 81 is 3^4 and also 9^2.
- The awesome card get, Set, contains 81 cards.
- 81 is the square of the sum of its digits. Thanks to this site.
- 81 is a heptagonal number and a 28-gonal number.
- There are 81 stable chemical elements.
Some more trivia about the number 81 appears here.
That concludes this month's Carnival of Mathematics. Oops, we've not mentioned our submissions. There are lots this month. Here they are ...
Mike Croucher, owner of the Carnival of Mathematics, presents A retrospective of 4 years of mathematical articles at WalkingRandomly. Happy Birthday, WalkingRandomly! I'm a big fan of Mike's blog and I discovered a bunch of neat articles among his most popular.
Mike Croucher also nominated these two articles:
Mathematica and Multimedia Blog Carnival #11 is up!
Mathematica and Multimedia Blog Carnival #11 is up at Love of Learning Blog.
Carnival of Mathematics #77 posted
Carnival of Mathematics #77 has just been posted at Jost a Mon.
Mathematics and Multimedia Carnival #4
Welcome to the fourth edition of the Mathematics and Multimedia Blog Carnival.

* Note: All images in this post are from Wikipedia.
The Number 4

- Four is the smallest composite number, its proper divisors being 1 and 2. Four is also a highly composite number. The next highly composite number is 6.
- Four is the second square number, the second centered triangular number.
- 4 is the smallest squared prime (p2) and the only even number in this form. It has an aliquot sum of 3 which is itself prime. The aliquot sequence of 4 has 4 members (4, 3, 1, 0) and is accordingly the first member of the 3-aliquot tree.

The Entries
(1) Jacqueline Barbour presents Teach addition so your child can remember it posted at Pain Free Math. A nice approach to using very simple props and a number line to teach addition and subtraction.

(2) Milo Gardner presents Ahmes Papyrus, New and Old Classifications posted at New and Old Ahmes Papyrus classifications,. The history of Western mathematics includes 200 rational number based problems recorded in Egyptian (2050 BCE to 1550BCE) unit fractions. The RMP is sometimes called Ahmes' Papyrus, named after its scribe. The hieratic text described 87 problems: 20 arithmetic, 10 algebraic, 10 geometric, 46 economic (weights and measures) and one mod 7 recreational problem known in the medieval era as "Going to St. Ives". Forms of unit fraction arithmetic remained in use until 1454 AD, the latest text was Fibonacci's Liber Abaci, Latin writing Europe's arithmetic book from 1202 AD to 1454 AD, and fully replaced by base 10 decimals by 1585 AD.

(3) Ed Pegg Jr presents Happy Vampire Day posted at Wolfram Blog. "October has a rather special day—10/05/2010 is a vampire date, since 10052010 = 5001 × 2010. The next two 8-digit vampire dates are 10/05/2064 and 10/19/2248. As a puzzle, try to figure out how to rearrange their digits into two 4-digit numbers, which have a product of the original number."

(4) zar presents Dimostrazione senza parole (demonstration without words) posted at Gli studenti di oggi. Zar's blog is written in Italian, but this particular post is "without words."

(5) Erlina Ronda presents GeoGebra and Mathematics: Investigating coordinates posted at Keeping Math Simple.

(6) John Golden presents Fraction Multiplication posted at Math Hombre -- A Geogebra visualization for multiplying fractions, along with a novice screencast and a discussion of embedding geogebra in a blog.

(7) William Emeny presents A sequences alternative to ‘how many matchsticks’ posted at Great Maths Teaching Ideas. "Make lessons on sequences much more interesting by adding context! Use sequences to analyse skyscrapers!"

(8) David Wees presents The Death of the Amateur Mathematician posted at Professional blog | 21st Century Educator. This is a discussion about what is happening in the field of education today.

(9) John Cook presents Variations on factorial! — The Endeavour posted at The Endeavour.

(10) Rebecca Zook presents How To Multiply Binomials Using a Box! posted at Triangle Suitcase - Rebecca Zook's Blog About Learning. "Many people find this "box" method for multiplying binomials more intuitive than foiling. I created this series of short videos to share this idea with other math teachers and students."

(11) Guillermo Bautista presents Mathematics in Microsoft Office « Mathematics and Multimedia posted at Mathematics and Multimedia. This is an article on integrating mathematics to office suites.

(12) Last but not least, I submit my own review of The Mystery of the Prime Numbers. This is an amazing book, with great illustrations that looks like a children's book but will appeal to anyone who wants to dive deep into simple ideas.

This concludes our third Carnival of Mathematics and Multimedia. The next Carnival will be hosted at the Math Hombre blog on November 8th. Submit your entries here.
Past Carnivals
Please Help Promote the Carnival
The Math and Multimedia Carnival is a baby carnival, so please promote this Carnival in your blogs.
Reminder: submissions due for Carnival of Mathematics and Multimedia
Just a reminder that your submissions are due Friday October 8 for the next Carnival which I'll be hosting the following Monday. More information about the Carnival is here.
Please submit your blog articles via the official submission form.
Mathematics and Multimedia Carnival #3 posted
The Mathematics and Multimedia Blog Carnival #3 has been posted. Starting next months the Carnival will travel. I'll be hosting #4 (a number that's easy to say something about.)
Please submit your articles using the official form.
Couple of carnivals and a clever clock conundrum
Two Math carnivals have recently been published:
- The 68th Carnival of Mathematics at +plus magazine
- The 2nd Mathematics and Multimedia Blog Carnival at the Mathematics and Multimedia Blog.
Now, here's a challenging adaptation of a problem I recently discovered. I won't reveal the source till later to not give away the problem.
There's something interesting about the time 2:26 and other times of the day. This interesting thing can be seen over 100 times per day. What is the property and exactly how many times does it occur in a day?
Carnival of Mathematics and Multimedia #1
Guillermo Bautista has launched the latest Math Carnival. The Carnival of Mathematics and Multimedia is hosted at Guillermo's Blog of the same name.
Carnival #1 has 23 entries, a very respectable number for a new (and even for a not so new) carnival.
Guillermo will be nurturing the new baby carnival at his site for a couple of months but is then open having it become a traveling carnival. Guillermo - I'll be happy to host one.
The carnival emphasizes the following kinds of articles:
- connections between and among different topics in mathematics as well connection of mathematics to other fields
- use of mathematics in solving real life problems
- clear, non-bookish conceptual explanations of mathematical concepts, particularly those which are hard to teach and difficult to learn
- integration of technology in teaching mathematics
- introduction of new software and Web 2.0 technologies
- software reviews and tutorials
[ Photo: Over the Fair by Lyn Columbe ]