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...
Followup to Favorite Proof
February 6, 2013, 12:00 amResults to Favorite Proof:
| What's your name/twitter? | Name of proof | Link to proof somewhere online... | Why do you like this proof? | Additional testaments of love for this proof | Additional testaments of love for this proof | ... | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| @dandersod | Eucl... |
Favorite Proof
January 25, 2013, 12:00 am“Whatever blows your hair back.”
So what’s your favorite proof? Why? Do me a favor and plug it into this spreadsheet, and in a couple of days I’ll put it to a vote.
Complex Numbers and Calculus
January 8, 2013, 12:00 amIf your computer can handle it, the things going on in this webpage are _amazing_: http://acko.net/blog/how-to-fold-a-julia-fractal/
— Daniel Schneider (@MathyMcMatherso) January 6, 2013
Astonishing work to put this webpage together.
More pizza?
December 16, 2012, 12:00 amFrom a review of a local pizza place:
Because of the easily laid out website, I could see that getting three 10-inch pizzas ($6 for plain cheese, $7 for pepperoni, and $9 for a house combo “Carcass” pie with sausage, bacon, pepperoni and meatballs) would result in more pizza and easier-to-handle...
Deadly Nightshade
October 8, 2012, 12:00 amOur baby is teething and while I was at the pharmacy, I saw a homeopathic remedy for teething babies with the following ingredients:
Belladonna, aka Deadly Nightshade, has what percentage of alkaloids? 0.0000000000003% or 3 x 10^-13%
Or if we take 1g of “medicine” then there are 3 femtograms,...