Thursday, October 21, 2010

Math problems of the week: 3rd grade Investigations vs. Singapore Math

I. From the 3rd grade Investigations Brain Challenges, Brain Puzzlers #3671:

II. From the final 3rd Grade Singapore Math money word problems, in Primary Mathematics 3B, p. 88:

II. Extra Credit:

Compare the challenges posed by the two sets of problems.


bky said...

The Singapore problems give straight-up mathematical challenges, which is appropriate since it is a math curriculum. The other set of problems gives another good sort of challenge: What information do you need to solve a certain problem? In general, I think this is a good part of a math curriculum, and one that Singapore K-6 does not address, to my recollection.

Nonetheless, I do not like the very first problem, since my answer would simply be, "No no no, I would never wear the stupid taco t-shirt for any savings whatsoever." The error in making such problems is in making them personal, so an answer such as mine would have to be acceptable. I think you have to make it precise what is to be optimized (monetary savings, or dignity).

FMA said...

No math calculation seems to be required to solve the taco problem. If the question was "you will only eat 4 tacos, so how much money will you save or lose by buying the t-shirt?" it would be fine. It seems like students are only being asked to guess the best option and considering the price of the t-shirt, I think this would be way too easy for most students. The problem could have been made much more challenging.

At least the second problem requires some calculation but is definitely very simplistic compared to the Singapore Math problems and wouldn't challenge most students.

Anonymous said...

The taco problem would be great as part of a critical thinking course. But it isn't really math. At least, not the kind students need in college or in math heavy fields like Engineering.

Anonymous said...

My impression is that the t-shirt promotion is offered every Tuesday, in which case it would be possible that the t-shirt would pay for itself. I think it would make a good problem for class discussion, but you would need a skilled teacher asking directed questions. As written, the question doesn't give students enough guidance to uncover the mathematical ideas.