Given that problem solving is lacking in public education and that is
exactly that which we as physics teachers try to evoke from students, I have
started to implement some brain teasers and riddles into my honors
curriculum. The problem is, they're a pretty sharp bunch of kids and I am
quickly exhausting my supply of problems. I had quite an archive; many
problems are sketchy, though: students try too hard to look for the "April
Fools" or ANY answer (sideways reasoning -- appropriate sometimes, but not
always) rather than following the intended structure of the problem itself.
Needless to say, I have had some intense sessions with students in which I
try to make them justify an answer; and even though their answer "fits," it
doesn't really follow the intent of the riddle. So they still want
"credit." (Not academic credit -- "bribes")
For example:
Two people are having a discussion. One says, "Based on the following
information, I want you to ascertain the age of my three sons."
a) the sum of their ages is thirteen.
b) the product of their ages is your age.
c) my oldest son weighs sixty-one pounds.
"Stop," the other says. "I know the ages of your sons."
What are their ages?
There are many answers; many, however, do not fit the "spirit" of the
riddle. Without making an inordinate amount of caveats and provisos I want
them to realize that, for example, that fractional ages don't count. Also,
one could say that their ages were 6, 4 and 3; but who ever heard of a
six-year-old that weighed sixty-one pounds?! With a little thought, I had
hoped they would arrive at the ages of 9 and a pair of two-year-old twins.
I would like to make a general call for your favourite brain-teasers and
riddles. They should be appropriate for the high-school student (no
in-depth statistics or probability, nor a specific knowledge of an
upper-divisional physics concept).
Thanks in advance,
nate davis
This posting is the position of the writer, not that of SUNY-BSC, NAU or the AAPT.