Anyone in FL know Mainland HS? - get them to fix their algebra page

[Stephen Tashiro]

A post on a math forum that I visit pointed out errors in an algebra tutorial in the Mainland HS algebra Lab site. The page is http://www.algebralab.org/lessons/lesson.aspx?file=Algebra_AbsoluteValueEquations.xm l (It gets both answers wrong for example ii.)

I thought that if I emailed the project manager of the pages about this that it would be fixed, but that didn't work. So I emailed again and CC'd everyone on the contact list for the the project. That didn't work either. Maybe I don't pass their spam filters. If anyone has a face-to-face contact there, please tell them.

[Chris Kennedy]

Oh, that's bad. And inexcusable.

I e-mailed from my work account -- I am assuming a .edu account won't get flagged as spam. If nothing happens, I may see if I can rustle up a phone number. The math prof in me is aggravated.

Cheers,

Chris

[Dan Hintz]

Hmmm... 7=-7, eh? Where's the black hole creation engine when you need it...

[Mike Henderson]

Okay, I looked at example ii and I don't see the problem. The answers I see are x= -2 and x = 8/3

Am I missing something in the math?

Mike

[John Coloccia]

Okay, I looked at example ii and I don't see the problem. The answers I see are x= -2 and x = 8/3

Am I missing something in the math?

Mike

Ditto. Looks OK to me, I think.

edit:
I had to look at it again after sipping my coffee. The right hand side can't ever be negative so neither answer could ever be correct, without even having to work it out. Anyhow, you always need to check your answers to be sure you have a solution, and in this case the equation has no solutions.

[Mike Henderson]

Okay, I see it now. If you substitute either solution back into the equation, you get [ |-7| = -7 ] or [ 7 = -7 ].

I did the math without doing the substitution back into the equation.

Mike

[Mike Cruz]

I told my algebra teacher that I would NEVER need this sort of stuff in "real life"...so I refuse to go the page, see the math, figure it out, and prove myself wrong and her right. I will NOT do ANY algebra now that I'm not in the 7th grade anymore. That's my story and I'm stickin' to it!!!!!!!!!!!!!!!!!!!!!!!:D

[Bruce Page]

I told my algebra teacher that I would NEVER need this sort of stuff in "real life"...so I refuse to go the page, see the math, figure it out, and prove myself wrong and her right. I will NOT do ANY algebra now that I'm not in the 7th grade anymore. That's my story and I'm stickin' to it!!!!!!!!!!!!!!!!!!!!!!!:D
The ONLY time algebra ever came up in my working career was when I had to take a mandatory Crane & Rigging class every 3 years! :rolleyes:

[Rick Moyer]

I always loved math; but a math forum, seriously? Isn't the Jedi warrior stuff enough?
Just kidding really. I didn't go to the link because I was nerdy in high school and hope I have evolved beyond that now,well maybe not. I'm not sure.

[Stephen Tashiro]

I always loved math; but a math forum, seriously? Isn't the Jedi warrior stuff enough?.

Yes, a math forum. In fact, two very good math forums are physicsforum.com (which has sections on mathematics) and sosmath.com/CBB/ (if you ignore the cheesy ads that the site sometimes has).

[Stephen Tashiro]

Correction - it's physicsforums.com (plural)

[Mike Cruz]

OMG, I can't believe I'm going there...but I will...

Rick, um, it's a Jedi KNIGHT, not a Jedi warrior...:o

[Rick Moyer]

OMG, I can't believe I'm going there...but I will...

Rick, um, it's a Jedi KNIGHT, not a Jedi warrior...:o
Hah! Believe it or not I never saw the whole Star Wars movie (1st one) or any of the sequals. After revisiting this thread I see I hadn't put a smiley in my first post, sorry Stephen. It was meant jokingly. Mike your post made me laugh.

[Mike Cruz]

Rick, I didn't think you needed a smiley. I thought your tone came through just fine...for me at least.

Funny, I just watched Star Wars episode IV (the original movie) in Blu-ray a couple of days ago. That movie never gets old.

[Belinda Barfield]

I told my algebra teacher that I would NEVER need this sort of stuff in "real life"...so I refuse to go the page, see the math, figure it out, and prove myself wrong and her right. I will NOT do ANY algebra now that I'm not in the 7th grade anymore.

I'm with Mike on this one. Y'all correct away, I'm too busy worrying about football.

[Chris Kennedy]

Well, I heard back from them saying that they had received my e-mail. Now let's see if it gets fixed.

[Stephen Tashiro]

Well, I heard back from them saying that they had received my e-mail. Now let's see if it gets fixed.

Thank you for your effort.

In the discussions on the math forum, some posters defend the method shown on that page and say that if followed by "check your answers", it would be acceptable. To me, "check your answers" is always a good idea, but the point of that is to guard against mistakes, not to fix the flaws in an incorrect method. It is pedagogical error to introduce a concept of "opposites" and to use a method that avoids teaching the definition of the absolute value function. However, 20 years ago (the last time I was involved with secondary education) I recall seeing the method they use taught in a high school textbook. I also recall arbitrating a dispute between a teacher who thought a "book answer" to a homework problem was correct and student, supported by a parent who was an engineer, who said it wasn't. The student was correct.

[Dave Anderson NH]

These types of things are difficult to fix due to ignorance and sloth. My youngest sister, now 53, is a EE with a masters in computer science. Her husband has a Phd in Ion implant physics. When my youngest neice was in an "enrichment" program at school years ago they started teaching basic physics to 5th graders. The school system purchased a package program developed for sale to schools by a local firm. Since my sister was interested in the education of her children she helped Maura with her homework. The ciriculum had the teachers (regular teachers working from the teachers program guide) defining MASS as a synomym for weight. My sister called the teacher to get the error corrected and getting nowhere since the teacher lacked even a basic understanding of almost anything scientifc, went to the principal who contacted the developer of the program who insisted weight and mass were the same. My brother in law got involved and wrote a letter to the school. After more BS by the program developers who it turns out had almost no science background, things escalated when my sister had a physics professor friend at Worcester Polytech write a letter to the school superintendent with a copy to the program developers. Eventually my sister gave up due to job committments and utter frustration in trying to clarify and explain scientific concepts and their importance to educators totally lacking in any science background

To make a long story short, the problem never did get corrected and as far as I know, the program is still in use today. The problem boils down to one of too many teachers with majors in education rather than in the subjects they teach. In the words of quality guru Edward Deming, "You don't know what you don't know."

[Stephen Tashiro]

To make a long story short, the problem never did get corrected

I hope it doesn't take Hurculean efforts to fix the algebra page. (I don't really have any stake in it. It's just an idle pastime.)

Another example of the same sort: Bill Nye's education DVDs may be, on the whole, very useful, but I'm not impressed by his treatment of math. On the DVD "Bill Nye The Science Guy:Probability , Classroom Edition", he says this about tossing a coin:

"We can't predict exactly how it's going to land on every toss, but we can predict exactly for a whole bunch of tosses. Eventually there will exactly as many heads as tails."

That's doesn't work out well if a student decides to toss the coin an odd number of times. Maybe he means you toss the coin till you get exactly as many heads as tails and then stop tossing it.

[Chris Kennedy]

These types of things are difficult to fix due to ignorance and sloth. My youngest sister, now 53, is a EE with a masters in computer science. Her husband has a Phd in Ion implant physics. When my youngest neice was in an "enrichment" program at school years ago they started teaching basic physics to 5th graders. The school system purchased a package program developed for sale to schools by a local firm. Since my sister was interested in the education of her children she helped Maura with her homework. The ciriculum had the teachers (regular teachers working from the teachers program guide) defining MASS as a synomym for weight. My sister called the teacher to get the error corrected and getting nowhere since the teacher lacked even a basic understanding of almost anything scientifc, went to the principal who contacted the developer of the program who insisted weight and mass were the same. My brother in law got involved and wrote a letter to the school. After more BS by the program developers who it turns out had almost no science background, things escalated when my sister had a physics professor friend at Worcester Polytech write a letter to the school superintendent with a copy to the program developers. Eventually my sister gave up due to job committments and utter frustration in trying to clarify and explain scientific concepts and their importance to educators totally lacking in any science background

To make a long story short, the problem never did get corrected and as far as I know, the program is still in use today. The problem boils down to one of too many teachers with majors in education rather than in the subjects they teach. In the words of quality guru Edward Deming, "You don't know what you don't know."

In Virginia, they have done away with undergraduate education degrees. To teach secondary school, you need to have a degree in the area (or closely related) with preferably a Masters in Teaching as a follow-up. For elementary, it is a degree in just about anything with a master's follow-up. Of course, there has been some movement locally to weaken one of the degree programs because the potential teachers are having trouble earning the bachelor's degree . . . .

Cheers,

Chris

[Mike Cruz]

Odd that this discussion has morphed into teaching, but here's my experience. The WORST teachers I've ever had were all......college professors. Mainly because many of them were brilliant in their fields, but couldn't teach their way out of a paper bag... Unfortunately, they get hired to do research, write articles, and publish. Teaching students was a byproduct necessary evil requirement for them. Many seemed to loathe being in those classrooms as much as we did!

[Greg Portland]

Odd that this discussion has morphed into teaching, but here's my experience. The WORST teachers I've ever had were all......college professors. Mainly because many of them were brilliant in their fields, but couldn't teach their way out of a paper bag... Unfortunately, they get hired to do research, write articles, and publish. Teaching students was a byproduct necessary evil requirement for them. Many seemed to loathe being in those classrooms as much as we did!I went to a well respected engineering school and they hired professors specifically to teach undergraduate classes and other professors for research. TAs had to pass a spoken and written English test that was not trivially simple.

[Greg Portland]

The ciriculum had the teachers (regular teachers working from the teachers program guide) defining MASS as a synomym for weight.Losing weight is easy, just jump up in the air to alter your force vector ;-). Unfortunately the weight reduction is short lived...

[Mike Cruz]

And I to a state college with 39,999 other students...and therein lies the rub!

[Belinda Barfield]

Losing weight is easy, just jump up in the air to alter your force vector ;-). Unfortunately the weight reduction is short lived...

Not if you jump enough times. :p

[Rick Moyer]

Not if you jump enough times. :p
Or far enough to escape gravity!

[John Coloccia]

These types of things are difficult to fix due to ignorance and sloth. My youngest sister, now 53, is a EE with a masters in computer science. Her husband has a Phd in Ion implant physics. When my youngest neice was in an "enrichment" program at school years ago they started teaching basic physics to 5th graders. The school system purchased a package program developed for sale to schools by a local firm. Since my sister was interested in the education of her children she helped Maura with her homework. The ciriculum had the teachers (regular teachers working from the teachers program guide) defining MASS as a synomym for weight. My sister called the teacher to get the error corrected and getting nowhere since the teacher lacked even a basic understanding of almost anything scientifc, went to the principal who contacted the developer of the program who insisted weight and mass were the same. My brother in law got involved and wrote a letter to the school. After more BS by the program developers who it turns out had almost no science background, things escalated when my sister had a physics professor friend at Worcester Polytech write a letter to the school superintendent with a copy to the program developers. Eventually my sister gave up due to job committments and utter frustration in trying to clarify and explain scientific concepts and their importance to educators totally lacking in any science background

To make a long story short, the problem never did get corrected and as far as I know, the program is still in use today. The problem boils down to one of too many teachers with majors in education rather than in the subjects they teach. In the words of quality guru Edward Deming, "You don't know what you don't know."

Geez. Not only is it WRONG, it completely obfuscates the fact that it is completely unknown why inertial mass and gravitational mass are equivalent. That's such an interesting thing to think about and it's completely ruined by this whole mass/weight thing. It also makes it just that much harder to relearn it the right way later on. Which school is this? I'm curious if they're still teaching this nonsense.

[Dave Anderson NH]

It was the Holden Mass school system John.

[Dan Hintz]

The ciriculum had the teachers defining MASS as a synomym for weight.
I go the simple route with these types of issues. Instead of a ton of lecture they will never understand, simply ask them "What's the mass of the Space Shuttle when it goes into space?" They can't say the weight is anything other than zero (close to it, anyway), because everything floats... and they can't say the mass is zero because the thing still exists. Ergo, mass cannot be the same as weight. Real world example with tangible, graspable, visualizable ideas, not theoretical mumbo jumbo that confuses halfwits like them.


The WORST teachers I've ever had were all......college professors. Mainly because many of them were brilliant in their fields, but couldn't teach their way out of a paper bag... Unfortunately, they get hired to do research, write articles, and publish. Teaching students was a byproduct necessary evil requirement for them. Many seemed to loathe being in those classrooms as much as we did!


I went to a well respected engineering school and they hired professors specifically to teach undergraduate classes and other professors for research. TAs had to pass a spoken and written English test that was not trivially simple.
Went to Purdue, a school known for pumping out researchers. Not teachers of the sciences, researchers. Big difference. There were a few choice teachers, but unfortunately they were few and far between. Mike's assessment is pretty much spot on. I would have given my left arm for a TA that spoke (understood?) English well in some of those classes, but the TAs were typically chosen because they spoke the native language of the professor they were working for. It's all about ease for the professor, not understanding of material by the student.

Hence, when Purdue comes asking for alumni donations, I sneer into the phone. I especially love it when the phone lackey says something similar to "Don't you want to give back to the institution that gave so much to you?" Sorry, that institution didn't give me anything, I had to pay through my eye-teeth to get it.

[Mike Cruz]

Hehe, Dan. My answer is a simple, "I already gave...for 5 1/2 years!" But I get that same "You want MORE?", feeling when they call...:mad:

[Chris Kennedy]

I got a reply -- it looks like they are going to fix it.

I apologize for the delay in responding to your email. Some years after getting this project going, we are a widely dispersed group and it takes time for us to react. That being said, we all appreciate your pointing out a mathematical error. The page is being taken down until we can replace it with correct examples. The intent was to use some simple examples and clearly a strict adherence to the definition of absolute value is necessary to tackle any problems of consequence.

Overall we have been pleased with reactions to this project. I use some of these pages with courses I teach at GA Southern and my students have found the content helpful. I hope you will alert us to any other concerns, especially with respect to mathematical content. We have made a serious effort to be correct, although not always "complete" in our approaches to these topics. For example, there is a more robust approach to synthetic division which we elected to omit using the KISS principle.

[Belinda Barfield]

I use some of these pages with courses I teach at GA Southern and my students have found the content helpful.


Well that certainly explains a lot!!!