Bill Waterson
May 20, 2013, 12:00 amThe truth is, most of us discover where we are headed when we arrive.
Must read advice from Bill Waterson on Brain Pickings, Maria Popova’s blog.
Your preparation for the real world is not in the answers you’ve learned, but in the questions you’ve learned how to ask yourself.
50 billion app downloads
May 2, 2013, 12:00 amOk. When is it going to hit 50 billion? Put your bets down.
Old posts from when Apple was at 25 billion app downloads.
More questions:
When will it hit 100 billion? 1 trillion? How many apps will be sold by December 25th? Any more?
Edit 5/11/13
More info:
Random Group Maker
April 18, 2013, 12:00 amNeat link: Team Maker
Allows you to paste in a roster and make random groups. No friction, no mess. Cool stuff.
Calculate Pi with Python
March 14, 2013, 12:00 amIntro to Computer programming worked at calculating digits of pi today. The actual algorithms aren’t too bad, but getting more than the standard number of digits from a double is a bit trickier. Here’s a program that calculates pi using:
Bailey–Borwein–Plouffe formula
Bellard’s formula
an...
Powers of 2 without a Zero
March 6, 2013, 12:00 am2^86 is largest known pwr of 2 that does not contain 0.What about other digits?Does each non-zero digit occur inf often among the pwrs of 2?
— James Tanton (@jamestanton) March 6, 2013
Interesting. The Intro to Programming Students gave a crack at this one; and after 30 minutes all were cl...
Reducing Prime
March 4, 2013, 12:00 amNumber theory nugget: 357686312646216567629137 is a prime number which remains prime after removing any number of digits from the left side!
— Maths World UK (@MathsWorldUK) March 4, 2013
Otherwise known as left-truncating primes with every suffix prime and no digit are zero. Here is the...
Oreo: Original vs. Double vs. Mega
March 3, 2013, 12:00 am[edit 8/20/13: New post with more data on the weights of Oreos and Double Stuf Oreos.]
[edit 8/21/13: And Part 3.]
Are Double Stuf Oreos really double stuffed? Some disagreement here: Chris Danielson in part 1 2 and 3 versus Chris Lusto in part 1 and 2.
Enter in the Mega Stuf...
Meteor Go Boom
February 17, 2013, 12:00 amHow far away is the meteor from this security camera when it explodes?
A Billion Heartbeats
February 9, 2013, 12:00 amAs animals get bigger, from tiny shrew to huge blue whale, pulse rates slow down and life spans stretch out longer, conspiring so that the number of heartbeats during an average stay on Earth tends to be roughly the same, around a billion.
And …
… the surface area a creature use...
Spirograph
February 6, 2013, 12:00 amSpirograph – @geogebra Tube bit.ly/XkaDL4 full frontal trochoid features. Maybe purges the obsession.
— John Golden (@mathhombre) February 6, 2013
Questions for students:
- What’s with that fraction on the left side? What does that do?
- How do I get a graph with 7 “ar...