What are some cool math and number facts that would blow the mind of a seven year old? [more inside]
posted by bondcliff on Dec 1, 2009 - 67 answers

In a talk (at TED) by Brian Greene on string theory he says that there are "there appear to be about 20 numbers that really describe our universe..." He lists a few in his talk, but what are the rest of of those numbers? [more inside]
posted by bigmusic on Oct 23, 2009 - 7 answers

Does anyone have experience with self-treatment as an adult with dyscalculia? I think I may have it, and that I've had it all my life. Whether or not that's so, are there any tricks to "rewiring" yourself? [more inside]
posted by anonymous on Apr 22, 2008 - 7 answers

My son asked me how many trees there are in the world. I know there are a finite number, yet I also know that it is not practical to count them. Same with grains of sand. When the set cannot be measured because it goes on forever we say the set is infinite. Is there a single word to express the concept of a countable, finite number too large to actually count? [more inside]
posted by JohnnyGunn on Nov 30, 2007 - 42 answers

Why is it hard for me to perform simple mental calculations with certain numbers? [more inside]
posted by lalex on Jun 5, 2007 - 19 answers

Can you help me with my innumeracy? [more inside]
posted by horseblind on Jul 23, 2006 - 16 answers

This page mentions, among other things, that "100 is the smallest square which is also the sum of 4 consecutive cubes." Obviously, this refers to the sum of 1^3 (1), 2^3 (8), 3^3 (27) and 4^3 (64). But it seems to me that the sequence can be pushed back to start with 0^3 (0), in which case you can get four consecutive cubes adding up to 36, which is a square. Is zero then not considered a cube? [more inside]
posted by ubernostrum on Mar 2, 2005 - 9 answers

I read The Curious Incident of the Bear in the Night-Time and one of the bits of cleverness is using primes to number the chapters. This got me thinking, is it possible to have a base prime number system? [math inside] [more inside]
posted by revgeorge on Sep 12, 2004 - 24 answers

The Number Zero: odd, even, or neither?
posted by Phatty Lumpkin on Jul 3, 2004 - 17 answers