Kaprekar’s constant

A student talked about Kaprekar’s constant (6174) during their my favorite presentation. Really cool. Steps (from wikipedia): Take any four-digit number, using at least two different digits. (Leading zeros are allowed.) Arrange the digits in descending and then in ascending order to get two four-digit numbers, adding leading zeros if necessary. Subtract the smaller number […]

Euclid GCD

Darker pixel = longer Euclidean algorithm to find GCD(x,y). Here x & y range from 1 to 500. So many questions… pic.twitter.com/k8N6jiGxSd — Matt Enlow (@CmonMattTHINK) September 24, 2014 I saw this toot by Matt yesterday morning and I loved the visual of the color based on the number of steps of Euclid’s GCD algorithm. […]

My Favorite for the Students

Let me know if these are things that interest you as a teacher of children: You want the students to find your subject interesting. You want the students to investigate your subject in their own time, like an adult would do. You want the students to continue to develop their presentation skills. You want the […]

Lizard Grow

My son was given this lizard as a big brother gift (can’t find online link to product, but here’s a similar toy). Thoughts? Original Size Size After 2 Day Soak Before Measurements Left image Length: 905 pixels Width (between front feet): 275 pixels 1 inch: 90 pixels Right image Height: 150 pixels 1 inch: 115 […]

M&M’s Mega

"'M&M's Mega' To Have Three Times More Chocolate." Oh brother here we go again. http://t.co/zrBE5tZ3Al /cc @dandersod — Dan Meyer (@ddmeyer) May 16, 2014 3x the Chocolate? What a great Calculus activity (hint: rotational volumes). Cross sections with an exacto: M&M M&M Mega What shape fits best? Click on image to get directly to the […]

Feedback On My Feedback System

Careful SBG, the all seeing eye of pershauron is trained on you: http://t.co/S6QAJz1p86 c/o @mpershan — Dan Anderson (@dandersod) May 19, 2014 In response to the Dark Lord Pershauron, I’ve decided to see what feedback you all have for my current SBG setup (v 5.0). The course is Pre-Calculus honors. There are about 40ish standards […]

Money Duck

This is a crosspost from my 180 photo blog. Introduction If you haven’t read Dan Meyer’s take on the Money Duck, go ahead and read up. Here’s some classroom action: Act 1 I presented the Money Duck to my PreCalculus H classes. We were in the midst of probability and we were moving towards probability […]

Mandelbrot Fractal v2

I had so much fun with the original Mandelbrot program that I decided to see if I could improve it. I was amazed by how easily I was able to generate a fractal picture that looked exactly like other pictures online. I didn’t look at anyone else’s code, just went down the path and the amazing […]

Mandelbrot Fractal

I was inspired by a My Favorite presentation from a student on the Mandelbrot fractal. I played around for a half hour at school without a ton of success, but I sorted out the sticking points on the way home, and finished it up tonight. Amazingly simple (the code may not look simple, but it’s […]

Chaos Game v2

I prepared a small demonstration of the Chaos gameĀ for some math teachers. First we used transparencies, markers, dice, and rulers, but humans are mistake-prone and slow. To The Computer! I decided to experiment with the rules of the game to see where it’d go. Human Error What happens when you bring in a random amount […]