Tuesday, December 23, 2014

Favorite Comments of '14, cont: GoogleMaster and ChemProf

On Math problems of the week: 4th grade 1920s math vs. Everyday Math:

GoogleMaster said...

I like that the problems don't come out even. Last week I had to explain to an Algebra I student whom I was tutoring that numbers aren't always "nice" in the real world. Her system of equations came up with an answer something like x = -11/6 and y = 9/2.

One of the things I like about this school: in the five or six times I have tutored there so far, I have yet to see a calculator. Students are expected to solve with pencil and paper, including the Alg I "solve by graphing" problems. Probably the more advanced students use calculators, but at the level that needs help, they don't get to use them.

I've found that it's not the fractions that trips the kids up so much as the negatives and positives. If -3x = 6, then what is x? I get responses like "6?" and "2?" Or, -11 minus 3 is what? "8?" So I go back to the number line ...
ChemProf said...
That's one of the things I find my students struggle with in applying algebra to chemistry. They can solve 2x + 1 = 5, but when the chemistry makes it 1.86x + 2.77 = 32.55, that's a whole different thing (even with calculators).

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