
small stellated dodecahedron
the second set of my daily twitter math problems, #26-50. answers can be found by scrubbing my twitter feed at twitter.com/dansmath
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Problem 26 (dan’s prime code):
Label the letters with first 26 primes; A=2, B=3, . . . , Z=101. What’s the value of DANSMATH? (eval. as in algebra)
Problem 27:
Review ‘dan’s prime code’, then find the (real) word whose prime code is closest to a million. (rules: two tweets max, closest=1.5, next5=1, rest=0.5.) Read the rest of this entry »
Posted by dansmath 




the teaching tree
May 1, 2009jeremy and emily factor a quadratic
I’m here at Cafe Wifi, with my triple latte and chocolate scone, thinking about my algebra students sitting there listening to me (or not), and I wondered: What about teaching a concept or giving out a problem, using the students themselves as tutors, in the following way:
Say a couple of students already know how to do something; for example, factoring the difference of cubes. They each explain it to someone, then those two explain it to two others, while the first two explain it to two other others.
As new students learn the skill, they move from the “don’t know” side of the room to the “know” side, with the explaining taking place at the interface where the tables are. From time to time, the newer knowers must explain it back to the early knowers to check they know it, and to gain insight into how the process changes.
Within a short number of generations, the whole class knows and the “don’t know” section is empty. Mission accomplished.
One concern is when a student doesn’t get the explanation and then gets bogged down trying to explain it to the next person. Maybe helping with that could be the role of the teacher, if there’s even one present.
Any comments on how you think this might or might not work? It wouldn’t have to be limited to math classes, right?