# IntMath Newsletter: Open source textbooks, math of beauty

By Murray Bourne, 14 Jan 2014

14 Jan 2013

In this Newsletter:

- Resource: Open source textbooks
- Updated math interactive - Math of beauty
- IntMath Polls
- Math puzzle
- Friday math movie - Sand images drawing machines
- Final thought - School for the soul

## 0. Greetings

Happy New Year, everyone! I hope 2014 is kind to you, and that you learn a lot.

I usually don't blog much during the end of year period, mostly because people are not very interested in math then! (How do I know? See Thanksgiving for less math where I show what happens to IntMath traffic each festive season.)

IntMath recently passed some milestones:

- There are now over 13,000 people subscribed to the IntMath Newsletter. Welcome to all of you, especially the newcomers!
- There are over 4,000 people following IntMath on Twitter. I used to think Twitter was a useless time sink, but now that I'm part of an educational community that shares lots of interesting and useful things, I've changed my mind.

I love hearing from readers and was delighted to receive this from Rachel in Ireland:

"Dear Murray

I have never met you in person, but you need to know how much help your IntMath Newsletters were to me whilst I was studying. I returned to college as a mature student so needed every bit of assistance I could get, and found that through your newsletter and site. Thank you so much."

You're very welcome, Rachel!

On with the Newsletter.

## 1. Resource: Open source textbooks

Unfortunately, this resource has since disappeared.

## 2. Updated math interactive - Math of beauty

This page has always been one of the most popular on IntMath. I updated it so it also works on tablets and (large?) smart phones.

This interactive allows you to place a mask over the photos of "beautiful" people, and see how close their face is to the "ideal". See: Math of Beauty (you'll find the mask interactive about 1/2 way down the page) |

**Skin deep? **On the page, I have a disclaimer that says "inner beauty is more important than external beauty.". As I said, this is not a serious piece of science!

## 3. IntMath Polls

Studies show one of the biggest impacts on student learning is the quality of the teaching. This poll is consistent with that finding.

The poll during Nov/Dec 2013 asked readers:

**What would have the biggest positive impact on your enjoyment of school?**

Better teachers: 44%

Learn more about real life issues: 34%

Reduce bullying: 11%

More technology: 11%

Total votes: **1200**

**Current IntMath Poll: **Considering the above result, the current IntMath Poll asks what teachers should do to improve learning outcomes. You can answer on any (inner) page of IntMath.com.

## 4. Math puzzles

The puzzle in the last IntMath Newsletter asked about the least 2 positive integers with certain remainders.

The question I asked is actually very old. It was posed by the Chinese military general, strategist and philosopher Sun Tzu in the 1st century CE. (Yes, the guy who wrote *Art of War*.)

Correct answers with explanation were given by Nicos and Hamid.

**New math puzzle**

A 2000-page book has pages numbered consecutively from 1. What percentage of the pages contain a 5 in the page number?

Leave your responses here.

## 5. Friday math movie: Four Cable Drawing Machine

This reminds me of Spirograph images that brought art and geometry together, and always had an element of mystery to them. Watch: Four Cable Drawing Machine |

## 6. Final thought: School for the soul

"Think of life as a school for your soul; you are here to learn in perfect well being. Here's a tip for life's pop quizzes: instead of asking why something happened, ask instead 'what can I learn?' For extra credit, ask '...and how may I serve?'" [Jackson Kiddard]

Until next time, enjoy whatever you learn.

See the 8 Comments below.