Behold the Prime Factorization sweater, knit by Sondra Eklund. It depicts the prime factorization of every number from 1 to 100.
Okay, look at the bottom row. It looks like there is a blank space on the left. That represents 1, because 1 is the background color, because 1 is a factor of every number. Next is a blue square, which represents 2. Next is a red square, for 3. Then comes 4. 4 = 2 x 2. So 4 is represented by two blue rectangles. Then comes 5. 5 is prime, so 5 gets a new color, yellow. Next is 6. 6 = 2 x 3. So 6 is represented by a blue rectangle and a red rectangle. 7 gets a new color, purple.
And so on. Click through for more pictures and explanation.
3.14 ways to celebrate Pi Day
- 1: Visit the San Francisco Exploratorium’s Pi Day celebration.
- 2: Watch the movie Pi on Netflix streaming.
- 3: Make one of Smitten Kitchen’s delicious pie recipies.
- .14: Ignore it, claim the real celebration is still three months away.
#mathtvshows
- Gomer Pi, USMC
- M*A*T*H
- The Golden Ratio Girls
- Differential Strokes
- X, Factored
- Jonaie Loves Fibonacci
- Prime Suspect
- Perfect Number Strangers
- Sinefeld
- Mathlock
- Three’s Prime
- Random Walking Dead
- Sons of Entropy
- Malcolm in the Midpoint
- Two and a Half Mean
- Everybody Loves Riemann
- Parity of Five
By Tony, Ellen, Luke and myself. What else you got?
If you divide 1 by 998,001 you get all three-digit numbers from 000 to 999 in order. Except for 998.
(via waldopepper on mlkshk)
A mathematical haircut makes an unambiguous statement to the world that you love math. Here, Nick Sayers is sporting a rhombic coiffure with interesting geometric properties. (via MAKE | Math Monday: Make a Mathematical Haircut)
Trig humor. Also available as a t-shirt.
Ninety / ten + twelve - three = Twenty + eleven - thirteen
From the archives: Puzzle #15: The Right Frame of Mind
(Originally posted April 9, 2010)
This puzzle looks like algebra, but is nothing of the sort. Where would you be if the following was true?
What percentage of people who have ever lived are alive today?
Over at the 1000 Memories blog, Jonathan Good poses that question and does some math to come to a reasonable answer.
Estimates suggest that it took 190,000 years for the population to reach 4 million (in a modern context that’s the number of people who ride the NYC subway each morning!). It wasn’t until the dawn of the industrial era in 1800 that our global population hit a seventh of what it is now, inching towards 1 billion. It’s rocketed ever since.
Before you click over, take a stab at a guess. The actual answer seems high to me, but then I asked a few people, and they all guess way higher. Seems like this is one of those questions that is completely without context, so any of a range of numbers could be plausible.
If you ever sat in geometry class wondering “What the eff is this all good for?” have a look at this video. It’s a compilation of nifty geometric objects, some just quirky fun, some supremely useful. They’re all part of a book called “How Round Is Your Circle? Where Engineering and Mathematics Meet.” Find out more at howround.com.
