# Month: May 2018

# Peer-reviewed math and science journal for kids

I’m filing this away for future reference: a peer-reviewed journal for explaining advanced concepts in science and mathematics to kids… and the peer reviewers are the kids.

Blog post: https://blogs.ams.org/matheducation/2017/12/11/communicating-advanced-mathematics-to-kids/

Journal: https://kids.frontiersin.org/

# Incredibly difficult math puzzle

For math/puzzle enthusiasts (as well for as my own future reference): This was one of the most diabolically difficult puzzles that I’ve ever seen. The object: use the numbers 1-9 exactly once in each row and column while ensuring that the given arithmetical operation in each cage is also correct. Here it is. Fair warning: while most MathDoku+ puzzles take me 20-40 minutes to solve, this one took me over 3 hours (spread out over 5 days).

# Solutions to Exercises in Math Textbooks

I read a very thought-provoking blog post on the pros and cons of having answers in the back of math textbooks. The article and comments on the article are worth reading.

https://blogs.ams.org/bookends/2017/10/11/solutions-to-exercises-in-math-textbooks/

# Rings and polynomials

# 5 Ways to go Beyond Recitation

Most students will encounter recitation in a math class during their academic career. How can math professors make the experience more meaningful? MAA Teaching Tidbits blog has 5 ways educators can enhance the student experience during recitation.

- Focus on getting students to do the work instead of doing it for them.
- Incorporate group work into your sessions.
- Get students to communicate what they understand to each other and to the class.
- Have students relate mathematics to their own experiences.
- Cultivate an environment where failure is ok and experimentation is encouraged.

Full article: http://maateachingtidbits.blogspot.com/2017/09/5-ways-to-go-beyond-recitation.html

# My Favorite One-Liners: Part 114

In this series, I’m compiling some of the quips and one-liners that I’ll use with my students to hopefully make my lessons more memorable for them.

I’ll use today’s one-liner whena step that’s usually necessary in a calculation isn’t needed for a particular example. For example, consider the following problem from probability:

Let be uniformly distributed on . Find .

The first step is to write . Then we start computing the expectations. To begin,

.

Ordinarily, the next step would be computing . However, this computation is unnecessary since will be multiplied by , which we just showed was equal to . While I might calculate if I thought my class needed the extra practice with computing expectations, the answer will not ultimately affect the final answer. Hence my one-liner:

To paraphrase the great philosopher The Rock, it doesn’t matter what is.

P.S. This example illustrates that the covariance of two dependent random variables ( and ) can be zero. If two random variables are independent, then the covariance must be zero. But the reverse implication is false.

# My Favorite One-Liners: Part 113

I tried a new wisecrack when teaching my students about Euler’s formula. It worked gloriously.