Spirographs

Hat tip to Jim Olsen and John Golden: Best spirograph app ever. http://t.co/lejJ7TQXw9 Thanks for the tip @DrOlsen314! — John Golden (@mathhombre) November 6, 2014 Great activity for kids (and adults) of many levels: How many rotations until the loop is closed?

Car Talk Annulus Puzzler

Awesome! RAY: This puzzler is from a fellow named Jerry Olsen. Ed and his two sons, Biff and Skip, have been hired to paint the floor of a merry-go-round. They want to make sure they measure the floor area exactly, because they don’t want to buy any extra paint. The carousel, of course, is a […]

Daily Desmos 3.0

Hello all, we’re looking to reinvigorate the Daily Desmos project and we’re looking for new contributors (and that means you!). We’re taking away the schedule and the numbering system so you can submit posts directly to DD whenever you’d like. You can still submit images via email, but we’re going to increase the number of […]

Edward Frenkel on Math and Beauty

Edward Frenkel, author of Love and Math, was on The Colbert Report. Here’s a transcript of an especially interesting segment: Edward Frenkel: When you say that you hate math, you’re really saying I hate the way math was taught to me. Imagine you’re in art class in which they only teach you how to paint […]

Power Series on Desmos

This is a crosspost from my Photo 180 blog. Power Series work in AP Calculus BC. Process: Since it’s a infinite series, look at partial sums to get an idea what this graph looks like. So look at … Perfect time to use technology. Texas Instruments Method Go to y1. Enter in . Graph. Wait […]

Brian Greene’s take on teachers.

My best teachers were not the ones who knew all the answers, but those who were deeply excited by questions they couldn’t answer. — Brian Greene (@bgreene) February 5, 2014 Fantastic.

Prime Matrix – Processing

Saw this tweet yesterday: All prime numbers between 2 and 2073600 mapped as pixels ARE THE MATRIX http://t.co/5skoRMc0gh — Kyle Hill (@Sci_Phile) January 14, 2014 Pretty cool. Josh Giesbrecht also did some great work with Mathematica to replicate the image. Thought that primes-looking-like-the-Matrix image might have been fake. Apparently not! (#Mathematica code included.) pic.twitter.com/LXFoTTNuyC — […]

Four and Five – Cartalk Puzzler

From cartalk. Ray: Get a piece of paper and write the number four, leave a little space, and write the number five. What common mathematical symbol, when placed between the numbers four and five, will result in a number that is greater than four but less than six? Tom: It has to be a mathematical […]

Super Ball

From Wikipedia’s entry on Super Balls. Wham-O Executive Vice-president Richard P. Kerr said, “Each Super Ball bounce is 92% as high as the last. Will it ever stop bouncing? Geometric sequences and series anybody? edit: Amazon review of a superball: What’s the bounce return rate?