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Time for Dozenalists to Celebrate?

A.D. (Tunesia) sent this note to me relative to the content provided on MathNEXUS: "Anything interesting planned for 12/12/12...perhaps at 12:12 and 12 seconds on that day?" I must admit I had not known this special moment was about to arrive....

Then, K.B. (Sumner) wrote: "I was wondering if you had any fun activities or ideas for 12-12-12?" I must admit that I have no file on 12-12-12.... So, why not create some teacher-based ideas for this special celebration....

First, focus on special properties of 12. Ask students to search out examples (with accompanying mathematical explanations)...some possibilities are:

• 12 is the smallest "abundant" number
• 12 is a "pentagonal" number
• 12 is smallest number with 6 factors
• 12 is a "superfactorial"
• 12 is a "sublime" number
• 12 is largest known even number expressible as the sum of two primes in one way (5 + 7), etc.
Some suitable resources are Archimedes fun website or Wikipedia's lengthy list or Stetson's list or these options. Do a search and you will find more...

Second, have students investigate the etymology of the word "twelve." For example, Wikipedia claims that "The word 'twelve' is the largest number with a single-morpheme name in English. Etymology suggests that 'twelve'...arises from the Germanic compound twalif 'two-leftover,' so a literal translation would yield 'two remaining [after having ten taken].' This compound meaning may have been transparent to speakers of Old English, but the modern form "twelve" is quite opaque. Only the remaining tw- hints that twelve and two are related."

Third, involve students in doing special things based on 12-ness...

• Make dodecagons (12-sided polygons) or dodecahedrons
• Force students to do all their math calculations using only base 12
• Look up the Dozenal Society, which wants U.S. to convert to using only base twelve instead of base ten
Fourth, ask students to explore why the number 12 is used so much in our society:
• 12 inches in a foot
• 12 months in a year
• 12 hours in a clock cycle
• 12 ribs in human body
• 12 people on a jury
• 12 knights on Round Table, etc.
Finally, get other non-math teachers involved in the movement:
• Look at and analyze movies such as Twelve Angry Men or Twelve Monkeys or Cheaper By the Dozen