I said
PPS, my former student aced his tests but skipped his homework, and is now repeating Algebra I. As soon as I can photocopy a few pages, I'll share some of the stupendous howlers I found on a quick perusal of his new text. Amazingly, it's *not* Prentice-Hall ...
Key Curriculum Press, Discovering Algebra, An Ivestigative Approach, by Murdock, Kamischke, & Kamischke. Along with a committee filling two columns on page ii, including five Multicultural and Equity Reviewers, two Social Sciences and Humanities reviewers, and, get this, three Scientific Content Reviewers, and one Accuracy Checkers (sic!). Seven hundred pages of irrelevant color pictures (e.g., Elvis impersonators) with inane captions (e.g., "Dead skin cells are one of the components of dust."). The people I know who are good at algebra had books with *zero* pictures, and few, if any, black and white graphs. Those books weighed maybe five times less, and contained way more than twice the algebra. (I learned it from my grandmother's.) If I were an aspiring algebra student, I would be deeply offended by this book for diluting the subject beyond recognition, as if algebra were so difficult and distasteful as to require huge doses of eye and brain candy, and for forcing me to lug to school hundreds of stupid pictures far less interesting than an equally heavy stack of magazines of my own choosing. And I came here to learn algebra, not to be cured of racism and sexism. And as a teacher faced with this book, I would invite any "student" who wished he was elsewhere to place his favorite magazine inside his open book. The pictures would be at least as relevant. I'll bet that even those who get an A in the course will be completely unable to apply algebra to any problem that appears to differ significantly from those "investigated" in the book. Howlers: In a section devoted to wind chill, p227, photo: snow blowing across highway across a barren plain. Caption: High wind speeds in Saskatchewan, Canada, drop temperatures below freezing. Just to make sure you understand, p228, photo: orange tents and heavily clad people on an expanse of snow. Caption: The wind chill factor drops temperatures well below zero in Antarctica. Wow, I had no idea how many of those poor Katrina victims must have frozen to death. According to this table, a temperature of 5F with a 20mph wind gives a chill of -31. So the temperature of an object at 0F should decrease rapidly. Think of the starvation we could avert by giving each victim a cheap refrigerator--a fan in a box! And those stupid citrus growers actually think they can avert frost damage with giant blowers! And imagine the wind chill at 40 below and 1000mph. It must be dang near minus infinity. And yet those idiot Europeans built the Concorde out of titanium because they thought aluminum would melt! Geez I'm glad I stayed in school. Oops, here in the main text it says wind chill is only how cold it *feels*. How do you measure how cold it feels? Does snow in Saskatchewan stay frozen because the wind makes it feel cold? In a section on radioactive decay, photo: human skull. Caption: Archaeologists can approximate the age of artifacts with carbon dating. This process uses the rate of radioactive decay of cabon-14. Carbon is found in all living things, so the amount left in a bone, for example, is an indicator of the bone's age. This is a plastic casting of a skull found in 1997 in Richland Washington. Carbon dating has dated this skull as 9200 years old. It's less frightening now that I know it's plastic. I wonder if the Scientific Content Reviewers and the Accuracy Checker used their real names. This skull, by the way, is of the infamous Kennewick Man, http://www.harbornet.com/folks/theedrich/hive/Kennewic.htm . Apparently, someone slipped it past the Multicultural and Equity Reviewers. In the fractals section, p19(!): As the Koch curve develops [For some reason, the book studiously avoids the name Snowflake], segment length decreases as the number of segments increases. As you draw higher stages, the length of individual segments approaches, or gets closer and closer to, what number? What number does the number of line segments approach? ZAP! Without even knowing it, the student has been infected with the poisonous notion that infinity is a number. And the poisonous notion that this line segment recursion actually defines which points are on the fractal. There is, of course, no mention of dimension. As a student, I would wonder how Mandelbrot and Sierpinski got so much credit for "discovering" designs that people have doubtless doodled since the invention of writing. The authors could have promised a discussion of dimension in a later chapter, although it might have required a few thousand more intervening pages of photographs. E.g., antique photo of seated woman. Caption: Maria Mitchell (1818-1889) was the first professional woman astronomer in the United States. Relevance: nil. But the Multicultural and Equity Reviewers must have detected a patch of inequity. I would think that even female students would begin to doubt the competence of women, if they require such heavy-handed propaganda. Side by side on p15, Caption 1: Because a coastline, like a fractal curve, is winding and irregular, it is not possible to measure its length accurately. The Koch curve can be used as a model of a coastline. [...] Photo: Aerial shot of a pair of beautifully smooth, crescent beaches! Then, to perfect the confusion, Caption 2: At later stages, the Koch curve looks smoother and smoother.[!] But if you magnify a section at a later stage, it is just as jagged as at Stage 1. So much for self-similarity. Photo: a minority adolescent holding a magnifying glass over a Snowflake approximation to reveal a part of the initial hexagram (Heaven forbid that I say Star of David), but with HUGE, FAT line segments! Line segments are the bane to understanding fractals. A properly drawn line segment is invisible! (Except as a color boundary.) p72, problem 9: The graph at right is a hexagon [True] whose vertices are seven[!] ordered pairs. Two of the points are (3,0) and (1.5,2.6). The hexagon is centered at the origin. a. What are the coordinates of the other points? HUH?? Assuming regular, even though it isn't? There are three kinds of mathematicians: ... To sum up, p295, Caption: Wall Drug is a landmark in South Dakota. The store's fame began during the 1930s--the Great Depression--when it offered free ice water to travelers. --rwg (Confidential to you-know-who-you-are: There is only one b in Fibonacci.) --------------------------------- Take the Internet to Go: Yahoo!Go puts the Internet in your pocket: mail, news, photos & more.