Thursday, August 12, 2010

An Ode to 24

Twenty-four is my favorite number. I'm not entirely sure why that is, except that maybe it's a remnant of playing too much "24" in middle school.



If you missed out on this math game phenomenon, it's quite simple: use all of the numbers on the card once and only once to get to 24. You had a whole deck, with Easy, Medium, and Hard difficulties, and you played against others (up to four players at a go). First person to get the right answer wins the card, whoever wins the most cards wins.

There are at least three different ways of getting to 24 with this pictured card. How many can you find? Read to the end to see my answer(s)!

24 Facts
  • 24 is the only number that is the product of all the numbers less than its square root.
  • 24 divides the difference between any two prime squares greater than three.
  • Subtracting one from each of its divisors (except 1 and 2, but including itself) yields a prime number - 24 is the largest number with this property.
  • 24 is the smallest abundant factorial.
  • 24 is factorial. (4!)
  • 24 = 23 x 3.
  • 24 has a unique representation as a sum of three squares: 24 = 22 + 22 + 42.
  • 24 is the smallest number with three representations as a sum of two distinct primes: 24 = 5 + 19 = 7 + 17 = 11 + 13.
  • 24 is the largest number divisible by all numbers less than its square root.
  • 24 is 44 in base 5.

(from Number a Day and NumberGossip)

Peacock Table Numbers


What I Like About 24
  • It's divisible by both 2 and 3 (and therefore 6).
  • Also, the digits add up to 6.
  • It's a multiple of 12. (I really like number that are multiples of 12, perhaps for their utility in measurements, counting time, etc)
  • The digits are multiples/factors/square roots of each other.
  • It's a multiple of both of its digits.



Twenty-Four Elephants Cross-Stitch Chart


24 game solutions:

  1. 4(2 + 3) + 4 = 24
  2. (4/2)(3)(4) = 24
  3. (4 * 4 * 3) / 2 = 24
  4. ...


What's your favorite number?

No comments:

Post a Comment