### Archive

Archive for the ‘Numbers’ Category

## Math Art: Cube Towers

This is “Prime Divisor Cube Towers on Ulam Spiral”, by Berhard Rietzl, on display at the 2012 Bridges Math and Art Conference at Towson University.

This is an artistic representation of the numbers 1 through 144:  each color represents a different prime divisor, and so each stack represents the prime factorization of the given number.

## 21022012

Happy Eur0pean Palindrome Day!

Expressing today’s date in the typical European style [ Day / Month / Year ] gives us a palindromic date!  Definitely a cause for mathematical celebration.  Or at least mathematical appreciation.

I admit that, as an American, this doesn’t resonate with me as much as another recent Palindrome Day, but it’s always nice to take a moment and appreciate a good number.

www.MrHonner.com

## 02/12/2012 — Another Permutation Day!

February 12, 2012 1 comment

Today we celebrate our second Permutation Day of the year!  I call days like today permutation days because the digits of the day and month can be rearranged to form the year.

We enjoyed our first permutation day of 2012 just 21 days ago.  Exactly three weeks apart!  That seems unusual.  I also wonder “How close could two permutation days be?”

Celebrate Permutation Day by mixing things up!  Try doing things in a different order today.  Just remember, for some operations, order definitely matters!

www.MrHonner.com

## 01/22/2012 — Happy Permutation Day!

January 22, 2012 1 comment

Today we celebrate our first Permutation Day of the new year!  I call days like today permutation days because the digits of the day and month can be rearranged to form the year.

We enjoyed several Permutation Days in 2011.  In addition to predicting future dates, an interesting question would be “Which year has the most Permutation Days?”

In honor of today, I recommend changing the order in which you do things!

www.MrHonner.com

## 2011: A Prime Year

December 31, 2011 1 comment

The year 2011 was quite remarkable, numerically speaking at the very least.  Here are some interesting facts about the number 2011.

First and foremost, 2011 is prime.  The last prime-numbered year was 2003 and the next will be 2017 (thank you WolframAlpha!).

What is more interesting is that 2011 is a prime that is the sum of eleven consecutive prime numbers!  This was first pointed out by @mathematicsprof.

Afterwards, it was pointed out by @republicofmath that 2011 is expressible as another sum of consecutive primes!

When will we see such a numerically interesting year again?

www.MrHonner.com

## 12102011

It’s been a fun few months for calendar math.  Today is another Permutation Day:  the month and day can be rearranged to form the year!

It certainly isn’t as exciting as the recent palindrome day, but it does make writing the date a little more fun!

www.MrHonner.com

## Worst Discount Ever

This has to be some kind of record for smallest difference between sale price and regular price.

Using the standard formula for percent change

we find the difference in sale price and original price to be

$\frac{119.99 - 119.00} {119.99} \approx 0.00825$

That’s a 0.8% discount!  Was this really worth printing up a “SALE!” sign?