I’ve always found it challenging to get students to draw the problems. I don’t understand their reluctance, I can’t imagine trying to keep the facts in my head, yet so many of them do just that. The result is that they miss details and make mistakes.
Today I saw a simple problem that I thought I would use as an introduction to drawing problems. The simple word problem says:
[Updated as used in class] There is a triangularly shaped park with trees along the edge. There is a tree at each vertex. Each side has five trees. How many trees are there all together?
Very simple problem if you just draw it. The answer is not 15.
I would’ve guessed 15, but knowing that is not the answer I imagined the park and came up with…12.
First time here, great blog… I teach chemistry so I am going to browse more later to look for useful resources
Thanks!
Comment by bioariel — September 11, 2009 @ 12:07 am |
Well-maybe.
No where in the question does it state that there are trees at the vertices of the triangle. There could easily be 5 trees located on each side with none at the vertices.
Comment by Andy — September 18, 2009 @ 7:41 am |
This is what happens when an unemployed engineer friend reads your blog. Ok Andy, you are in charge of rewriting the question. Get to work.
Comment by Scott — September 18, 2009 @ 4:13 pm |
I changed the question and simplified the sentences. This worked better, I said each short sentence with a pause so they could internalize the information. They still guessed 15 until somebody drew it.
Comment by Scott — September 26, 2009 @ 6:50 am |
I like it better this way. Glad to hear that they knew what a vertex was.
Comment by Andy — September 28, 2009 @ 5:44 am |
ALWAYS DRAW A PICTURE haha
http://www.peebleslab.com/42
(from my webcomic)
Comment by Andrew — October 22, 2009 @ 6:13 pm |
Andrew-
Not sure if you are trying to make a joke or not, but your website cartoon is in error. A 2.5 angle of elevation would imply that the other angle at the observer is 2.5 degrees, or that the one you have labeled 2.5 is really 87.5 degrees. The answer comes out to 1603 ft.
This assumes he measures the elevation angle from the same level as the base of the lighthouse.
Comment by Andy — October 22, 2009 @ 8:01 pm |
yeah…
see the joke is he incorrectly labels the angle of elevation… haha oh well I tried
Comment by Andrew — October 22, 2009 @ 8:03 pm |
Sorry. Of course anyone that lets a 3″ tall guy drive a motorboat is asking for trouble anyway.
Comment by Andy — October 22, 2009 @ 8:05 pm |