**21st edition of the Math and Multimedia Carnival**! I hope you enjoy the selection of mathematics-related topics that have been included in the carnival this month, which have either been submitted via the blog carnival submission site, emailed to me, or are of my personal choosing. Before we get to those though, as is tradition for the

**Math and Multimedia Carnival**, let's learn some trivia about the number 21!

**Triva about the Number 21**:

- 21 is a Fibonacci number, whereby is it the sum of the preceding two numbers (8 and 13) in the Fibonacci sequence.
- We are currently living in the 21st century.
- The element with the atomic number 21 is Scandium.
- The name of pop singer Adele's second album is titled "21".
- In most US states, 21 is the legal drinking and gambling age.
- Coincidentally enough, 21 is another name for the popular card game, Blackjack.
- A popular restaurant in New York City is named "21 Club".
- A standard, 6-sided die has a sum of 21 total spots.
- Here's a strange one. According to Dr. Duncan MacDougall, a 20th century American physician, a person's soul is a physical component of the body, and has a weight of 21 grams.

And now, on to my collection of math articles! I hope you enjoy them!

**Technology and Mathematics**Colleen Young has submitted a list of some of the best online tools to help learning, in her post "

*Top 100 Tools 2012 - voting open*." The article is hosted on her site

*Mathematics, Learning and Web 2.0*, and contains a link to vote for your favorite learning tools of the year.

Amongst several other great articles on the subject of technology in education, Mark Gleeson has a very interesting read up on his site, titled "

*The iPad and Maths - Are We There Yet? Pt 2 (non-Math apps do the job?),"*which he has up on his website

*Mr G Online*.

__Mathematics Education__John Golden has submitted a post titled "

*Two Teacher Tech Topics*" from his

*math hombre*site. This article takes a look at teachers' attitudes towards the use of calculators in mathematics, and also shares some thoughts on reflective writing or blogging as a means to strengthen learning.

Diana Clerk has provided a nice round up of some extremely useful sites and resources in her post titled "

*20 Best Sites for Helpful Dissertation Tips*." You can find plenty of tips and advice from these sites to help you complete one of the most difficult parts of a Ph.D. program. This submission is hosted on the

*Online Ph.D. Program*website.

__General Mathematics__Guillermo Bautista, the creator of the Math and Multimedia Carnival, submitted a pair of blog entries. The first is titled "

*Divisibility by 8*" and outlines a shortcut for dividing large numbers by 8. This entry is posted on his website,

*Mathematics and Multimedia*. Speaking of large numbers, his second post provides a commentary on "

*The Use of Large Numbers*," which is posted on his

*Mathematical Palette*blog.

Kalid Azad provides a very helpful article that undoubtedly will be of use to many students: "

*Vector Calculus: Understanding the Dot Product*." I wish my physics class (back in the day) explained vector math as well as this post. He even throws in a reference to the speed boost pads found in Nintendo's Mario Kart, to keep things current! He has this posted on his site,

*Better Explained*.

Warren Davies has provided an answer to a common question asked by students in the field of statistics: "

*What the hell is Bonferroni correction*?" This short post explains the Bonferroni correction and its role in data error analysis, and is hosted on his "

*Generally Thinking Data Blog*."

Rick Regan has a fantastic four-part series on binary arithmetic up on his website

*Exploring Binary*. The latest in his series is "

*Binary Multiplication,*" which follows articles on addition and subtraction, among other incredibly informative works on the topic of binary numbers.

One of my submissions to this blog carnival is titled "

*Inverse Trig Functions,"*in which I discuss how to find an unknown angle when given the value of the standard trigonometric function. This article is posted elsewhere on this site,

*Math Concepts Explained*. My second submission is a post about "

*Pythagorean Identities*" and how you can derive them, which I have up at the

*In Mathematics*blog.

**!**

__And that concludes the 21st edition of the Math and Multimedia Carnival__I hope that you have enjoyed the variety of articles, and perhaps learned a little something new as well! Thank you to all of the authors who submitted their works, and also to those who gave me permission to repost their pages. The 22nd edition is just around the corner, so here's to the continued success of the Math and Multimedia Carnival!