kitchen table math, the sequel: math wars
Showing posts with label math wars. Show all posts
Showing posts with label math wars. Show all posts

Friday, May 29, 2015

Math in the real world

Excerpt from:
Multiple Numeric Competencies: When a Number Is Not Just a Number
by Ellen Peters & Par Bjalkebring
Journal of Personality and Social Psychology
May 2015, Vol. 108, No. 5, 802–822
Jeff is a friend of one of the authors and a highly skilled carpenter who claims he is “no good at math.” He excels, however, at estimating the angles, lengths, and areas that are critical to his craft. Ruth, a smart and personable woman in her 70s, broke down crying while attempting to answer questions about numeric data in a Medicare insurance choice experiment. She explained through tears that she was “not a numbers person” and that her husband always did such tasks for them until his death 2 years prior. Numbers were fraught with emotion for her. Individuals like Jeff and Ruth are common. Although students often ask why they should learn math and whether it will ever be useful, Jeff and Ruth provide examples of the importance of everyday math, belief in one’s numeric ability, and (in Jeff’s case) how compensatory numeric skills might exist.

Making good choices in life often involves understanding and using numeric information (Hibbard, Peters, Slovic, Finucane, & Tusler, 2001; Thaler & Sunstein, 2003; Woloshin, Schwarz, & Welch, 2004). Choosing the best health insurance involves calculating likely annual costs from monthly premiums, deductibles, and office and pharmacy copayments. Making an informed decision about a medical treatment or screening option requires understanding risk and benefit information (including their probabilistic nature). Such numeric data are provided to facilitate informed choices, but numbers can be confusing and difficult for even the most motivated and skilled individuals, and these issues are exacerbated among the less numerate. In the present article, we explore the value of explicitly considering multiple measures of numeric competence—objective numeracy, subjective numeracy, and the mapping of symbolic numbers. We review their likely interrelations, test their possible dissociable roles in evaluations and decision processes, and consider future directions in personality and social-psychological processes.
I find the image of a woman in her 70s crying over math profoundly sad.

I guess that's what I was trying to say about my years reteaching math at home--about not getting what I wanted, but getting what I needed instead. (scroll down to end of post)

After all the crying shouting over math around here during the middle years, I'm pretty sure I managed to raise a child who does not, at this point, define himself as "no good at math."

It wasn't easy.

But it was definitely fun.

Friday, February 28, 2014

Really existing Common Core

Part 1: Help Desk, Common Core edition

Our high school principal explains the centrality of modeling to high school math:
55:23 This is a very important slide and one that you’ll hear me talk about a number of times.

Because modeling, we really look at modeling as the way to really permeate through all of the different levels of mathematics at the high school level. And we really look at it from a standpoint of pedagogy. When we talk about modeling, what we’re really talking about is the conceptual side of mathematics. Recently, and there’s been a shift to a very computational format for teaching mathematics, especially at the high school level. And that’s where we would start to break things down and scaffold them into very fine points. But what we have found is mathematics teachers over the last 10, 15, 20 years, when this pattern was happening, was that students were starting to learn their broader understandings of mathematics. 56:19 There was a big need to pull back and get back to the point of teaching to deeper understanding and to the conceptualization of math, not just about being able to compute the correct answer. So modeling we really look at as the link to be able to do that. It’s the opportunity to create real-life problem-solving situations where students need to understand the conceptualization of what’s going on in the math as well as how it relates to the real world.

Geometry, obviously, is when we start talking about shapes and sizes and the relative position of objects, and statistics and probability gives us the opportunity to start looking at mathematics and creating analysis and really looking into the chances of opportunity and things occurring.

57:07 So again, as I mentioned, modeling becomes a real important focal point for us. And the phrase that we’ve been talking about is it becomes this umbrella for us. It’s the umbrella that brings the whole mathematics curriculum at the high school level together, and a way for us to keep progressing through and thinking about how it matches up. So when we think about constantly naming and reinforcing the work that the students are doing we want to constantly bring them back as well to these broader-scale concepts. 57:39 So this slide and the next slide starts to talk about that even within those conceptual designs that I mentioned before, even within algebra, there’s an aspect of modeling that’s critical and important for them to understand in the algebra as well as the other mathematical concepts within.

Similarly you have functions here, and again, there are pieces of it that we pull out and we understand how do we create real-life conceptualization and contextualization for our students so that when they’re working through this, they understand again not just the specific calculation of an equation or formula but what it really relates to.

Similarly we do the same things in geometry and we do the same things in statistics and probability. Again, for me, this is about teaching to big ideas and perspective. We’ve been talking at the school about deep understanding and I said that would be one of those shifts that we keep coming back to, and I think that that’s really one of the most important messages that we can deliver about the mathematics instruction and how the Common Core starts to create a shift for us.

Irvington UFSD School Board Meeting - February 11th, 2014
This strikes me as fundamentally wrong, but if you guys tell me it's sound, I'll have to revise my view.

My understanding of math, of what math is, is that …. mathematics is not essentially, or even first and foremost, a system for representing empirical reality. The fact that math so powerfully -- and so eternally -- does capture many aspects of empirical reality is, in my view, either a) beside the point, or b) creepy.

Math, as I think of math, has a mathiness that cannot be reduced to modeling; math is a thing unto itself and should be taught as a thing unto itself -- or, at least, students should be made aware of the fact that to a mathematician math is not just a code-writing tool.

(Again, setting aside the possibility that math is just a code-writing tool.)

"Constructionism"

Constructionism is a philosophy of education in which children learn by doing and making in a public, guided, collaborative process including feedback from peers, not just from teachers. They explore and discover instead of being force fed information, or subjected to a regime of social control as in the Prussian system adopted in the US and elsewhere, sometimes called Instructionism. Constructionist guidance has to be informed by a knowledge of what there is to explore and discover, including our ignorance, and of a variety of approaches that can be used for children at different developmental levels with various degrees of preparation.

More on this topic can be found by exploring Google using keywords such as "constructionism", "education", "philosophy". See for instance openworldlearning, Seymour Papert's website, http://www.papert.org , and the wikipedia article on constructionist learning. Constructionism is implemented on the OLPC XO in the form of collaborative discovery.

"I hear and I forget. I see and I remember. I do and I understand." - Attributed to Confucius.

Constructionism is built on the foundation of Constructivism, the theory of childhood learning created by Jean Piaget, Lev Vygotsky, and many others.

One Laptop Per Child
No fun.

Sunday, February 9, 2014

Onward and upward

In The Economist:
Estonia’s government has commissioned Mr Wolfram’s consultancy in Oxfordshire to modernise maths courses for secondary-school pupils. Starting this month, it will pilot lessons built around open-ended problems which have no single solution. One example: “What’s the best algorithm for picking a romantic date?” (Possible answer: go on more dates with a lower quality threshold to maximise the chance of success.) Another: “Am I drunk?”, which leads into quantitative analysis involving body masses, rates of alcohol absorption and other variables.

Time for a Ceasefire | Feb 1st 2014 | SHANGHAI AND TEL AVIV

Sunday, January 12, 2014

The law of universal linearity

Interesting discussion

I was struck by this passage:

In terms of implementing this in practice, I think that college is way too late, and also quite difficult because college math (and STEM) courses tend to be mostly about transmitting massive amounts of boring technical content and technical skills, leaving little to no room for actual ideas or ways of thinking. Nevertheless, I do think it would be an interesting experiment to have students keep something akin to a "vocabulary notebook" where they record the meaning (as opposed to the formal definition) of the various kinds of expressions they run in to. For example, a fraction ab is supposed to mean "a number which when multiplied by b gives a"; it is short and illuminating work to figure out from this (using distributivity of multiplication over addition, which we definitely want numbers to satisfy) that ab+cd=ad+bcbd, that there is no number meant by a0, and that 00 can mean any number). This of course, presupposes that somebody takes the time and makes sure that the language in which these meanings are explained is coherent, so it would be a lot of work to design a course around this method.

I did in fact once successfully disabuse a(n Honors Calculus) student of "the Law of Universal Linearity" using these ideas. The particular instance concerned manipulating the Fibonacci sequence, and the student had made the error of writing something like Fx+Fx=F2x. What I did is explain the stuff above and had the student apply them by analyzing the meaning of the various expressions he had written down was, and then ask whether that equality was justified based on what he knew the expressions meant. That seemed to make an impression on the student, but I personally believe it was an impression made ten years too late...

Friday, January 11, 2013

Jo Boaler should release her data

background: Educational malpractice for the sake of reform math

FERPA protects the identities of individual students, not schools.

If FERPA protected the identities of schools, No Child Left Behind would be illegal. Clearly it is not.

Ms. Boaler should release her data.

Friday, October 19, 2012

a math revolution too

Barry's in the Atlantic!

why do students have to sit on the floor

I'm watching the Jo Boaler video, which I see was funded by the Educational Advancement Foundation, a nonprofit dedicated to imposing its ideology on other people's children (1) the development and implementation of inquiry-based learning at all educational levels in the United States, particularly in the fields of mathematics and science, and (2) the preservation and dissemination of the inquiry-based learning methodology of Dr. R.L. Moore (1882-1974).

Immediately, it struck me: students sitting on the floor. Again. I see this constantly in informational videos about inquiry-based classrooms.

Why?

Has no one in our history managed the feat of inquiring while seated at a desk?

re: the "harrassment and persecution" accusations Boaler has posted on a Stanford University website.

I have been married to a university professor for my entire adult life, and I've never seen anything like this. Stanford should direct Boaler to host her complaints on a personal website, and Milgram and Bishop should consult attorneys.

The Bishop/Clopton/Milgram critique of Boaler's research is entirely professional in content and in tone. The following is an excerpt:
Dr. Boaler kept the names of the schools private and asked that everyone trust that she had faithfully recorded the outcomes of her study. We were able to determine the identities of these schools. Then we studied the considerable amount of data in the California data base relating to these schools, as well as data requested through the Freedom of Information act or the California Public Records Act. This data includes things like school rankings, demographic data, SAT I outcomes, AP outcomes and even student level outcomes. Further, the results of the students from each of these schools on the entry level CSU4 math skills test are available. The totality of this data does not support her conclusions.

Indeed, there is only one year in the last five where any of these various measures for any cohort of students gives any advantage to the Railside students - the CST5 Algebra I exams for the ninth grade students in 2003 - and this is the only test data from that California database which is reproduced in Prof. Boaler’s report even though these data cannot represent the cohort that is the focus of the report.

We also found evidence that Dr. Boaler obtained her results by focusing on essentially different populations of students at the three schools. At Railside, her population appeared to consist primarily of the upper two quartiles, while at the other two schools the treatment group was almost entirely contained in the two middle quartiles.

A Close Examination of Jo Boaler’s Railside Report
Wayne Bishop
Dept. of Mathematics Cal. State University, LA
Paul Clopton VAMC
San Diego
R. James Milgram
Dept. of Mathematics Stanford University
Jo Boaler should provide her data to other researchers.

Friday, August 10, 2012

Knowledge of fractions & division predict success in algebra

When I first started writing kitchen table math, with Carolyn Johnston, Carolyn told me that fractions are the math cliff.

Yesterday, Glen left a link to a new study in Psychological Science confirming the critical importance of fractions -- and long division -- to a child's future success in algebra:
Our main hypothesis was that knowledge of fractions at age 10 would predict algebra knowledge and overall mathematics achievement in high school, above and beyond the effects of general intellectual ability, other mathematical knowledge, and family background. The data supported this hypothesis.

and:

Early knowledge of whole-number division also was consistently related to later mathematics proficiency.

and:

The greater predictive power of knowledge of fractions and knowledge of division was not due to their generally predicting intellectual outcomes more accurately.
More from the article:
ABSTRACT
Identifying the types of mathematics content knowledge that are most predictive of students’ long-term learning is essential for improving both theories of mathematical development and mathematics education. To identify these types of knowledge, we examined long-term predictors of high school students’ knowledge of algebra and overall mathematics achievement. Analyses of large, nationally representative, longitudinal data sets from the United States and the United Kingdom revealed that elementary school students’ knowledge of fractions and of division uniquely predicts those students’ knowledge of algebra and overall mathematics achievement in high school, 5 or 6 years later, even after statistically controlling for other types of mathematical knowledge, general intellectual ability, working memory, and family income and education. Implications of these findings for understanding and improving mathematics learning are discussed.

[snip]

Marked individual and social-class differences in mathemat- ical knowledge are present even in preschool and kindergarten (Case & Okamoto, 1996; Starkey, Klein, & Wakeley, 2004). These differences are stable at least from kindergarten through fifth grade; children who start ahead in mathematics generally stay ahead, and children who start behind generally stay behind (Duncan et al., 2007; Stevenson & Newman, 1986). There are substantial correlations between early and later knowledge in other academic subjects as well, but differences in children’s mathematics knowledge are even more stable than differences in their reading and other capabilities (Case, Griffin, & Kelly, 1999; Duncan et al., 2007).

These findings suggest a new type of research that can con- tribute both to theoretical understanding of mathematical development and to improving mathematics education. If researchers can identify specific areas of mathematics that consistently predict later mathematics proficiency, after controlling for other types of mathematical knowledge, general intellectual ability, and family background variables, they can then determine why those types of knowledge are uniquely predictive, and society can increase efforts to improve instruction and learning in those areas. The educational payoff is likely to be strongest for areas that are strongly predictive of later achievement and in which many children’s understanding is poor.

In the present study, we examined sources of continuity in mathematical knowledge from fifth grade through high school. We were particularly interested in testing the hypothesis that early knowledge of fractions is uniquely predictive of later knowledge of algebra and overall mathematics achievement.

One source of this hypothesis was Siegler, Thompson, and Schneider’s (2011) integrated theory of numerical development. This theory proposes that numerical development is a process of progressively broadening the class of numbers that are understood to possess magnitudes and of learning the functions that connect those numbers to their magnitudes. In other words, numerical development involves coming to understand that all real numbers have magnitudes that can be assigned specific locations on number lines. This idea resembles Case and Okamoto’s (1996) proposal that during mathematics learning, the central conceptual structure for whole numbers, a mental number line, is eventually extended to rational numbers. The integrated theory of numerical development also proposes that a complementary, and equally crucial, part of numerical development is learning that many properties of whole numbers (e.g., having unique successors, being countable, including a finite number of entities within any given interval, never decreasing with addition and multiplication) are not true of numbers in general.

One implication of this theory is that acquisition of fractions knowledge is crucial to numerical development. For most children, fractions provide the first opportunity to learn that several salient and invariant properties of whole numbers are not true of all numbers (e.g., that multiplication does not necessarily pro- duce answers greater than the multiplicands). This understanding does not come easily; although children receive repeated instruction on fractions starting in third or fourth grade (National Council of Teachers of Mathematics, 2006), even high school and community-college students often confuse properties of fractions and whole numbers (Schneider & Siegler, 2010; Vosniadou, Vamvakoussi, & Skopeliti, 2008).

This view of fractions as occupying a central position within mathematical development differs substantially from other theories in the area, which focus on whole numbers and relegate fractions to secondary status. To the extent that such theories address development of understanding of fractions at all, it is usually to document ways in which learning about them is hindered by whole-number knowledge (e.g., Gelman & Williams, 1998; Wynn, 1995). Nothing in these theories suggests that early knowledge of fractions would uniquely predict later mathematics proficiency.

Consider some reasons, however, why elementary school students’ knowledge of fractions might be crucial for later mathematics—for example, algebra. If students do not under- stand fractions, they cannot estimate answers even to simple algebraic equations. For example, students who do not under- stand fractions will not know that in the equation 1/3X = 2/3Y, X must be twice as large as Y, or that for the equation 3/4X = 6, the value of X must be somewhat, but not greatly, larger than 6. Students who do not understand fraction magnitudes also would not be able to reject flawed equations by reasoning that the answers they yield are impossible. Consistent with this analysis, studies have shown that accurate estimation of fraction magnitudes is closely related to correct use of fractions arithmetic procedures (Hecht & Vagi, 2010; Siegler et al., 2011). Thus, we hypothesized that 10-year-olds’ knowledge of fractions would predict their algebra knowledge and overall mathematics achievement at age 16, even after we statistically controlled for other mathematical knowledge, information-processing skills, general intellectual ability, and family income and education.

Early Predictors of High School Mathematics AchievementRobert S. Siegler1, Greg J. Duncan2, Pamela E. Davis-Kean3,4, Kathryn Duckworth5, Amy Claessens6, Mimi Engel7, Maria Ines Susperreguy3,4, and Meichu Chen4Psychological Science 23(7) 691–697

Friday, June 22, 2012

in the leafy suburbs

Eighteen months into my job as the first woman director of policy planning at the State Department, a foreign-policy dream job that traces its origins back to George Kennan, I found myself in New York, at the United Nations’ annual assemblage of every foreign minister and head of state in the world. On a Wednesday evening, President and Mrs. Obama hosted a glamorous reception at the American Museum of Natural History. I sipped champagne, greeted foreign dignitaries, and mingled. But I could not stop thinking about my 14-year-old son, who had started eighth grade three weeks earlier and was already resuming what had become his pattern of skipping homework, disrupting classes, failing math, and tuning out any adult who tried to reach him. Over the summer, we had barely spoken to each other—or, more accurately, he had barely spoken to me. And the previous spring I had received several urgent phone calls—invariably on the day of an important meeting—that required me to take the first train from Washington, D.C., where I worked, back to Princeton, New Jersey, where he lived. My husband, who has always done everything possible to support my career, took care of him and his 12-year-old brother during the week; outside of those midweek emergencies, I came home only on weekends.

Last spring, I flew to Oxford to give a public lecture. At the request of a young Rhodes Scholar I know, I’d agreed to talk to the Rhodes community about “work-family balance.” ... What poured out of me was a set of very frank reflections on how unexpectedly hard it was to do the kind of job I wanted to do as a high government official and be the kind of parent I wanted to be, at a demanding time for my children (even though my husband, an academic, was willing to take on the lion’s share of parenting for the two years I was in Washington). I concluded by saying that my time in office had convinced me that further government service would be very unlikely while my sons were still at home.
Why Women Still Can't Have It All
by Anne-Marie Slaughter
Atlantic Monthy | July-August 2012
Anne-Marie Slaughter is talking about a phenomenon I never see addressed in popular articles about "balancing work and family": the teen years are the hard ones. Or can be. When I was young the feminist model was: stay home for 3 or 4 months while you're nursing, then go back to work. The demanding years were assumed to be a child's pre-school years; once the child reached school age, you were 'done,' in a sense. It made sense to work outside the home at that point.

That always struck me as wrong, even before I had kids. My question was always: so when your child turns 13 and goes sprong, where are you? Not that all children go sprong at age 13. C. didn't, and thank God for that. Nevertheless, plenty of kids do go sprong, and if you have more than one child, that would seem to raise the odds of your someday being the parent of a teenage kid who has come unglued.

So I like the fact that this high profile woman has actually spoken, out loud, about what happens to a high profile career when a teenager is in distress.

That said, I was struck by the list of problems Ms. Slaughter's son is having:
  • skipping homework
  • disrupting classes
  • failing math
  • tuning out adults who try to reach him
With the possible exception of the fourth item, all of these issues are school problems, requiring school solutions.

You can see this easily if you imagine a 14-year old student who has no parents, or, alternatively, has parents who are dysfunctional. When that student skips homework, disrupts classes, fails math, and tunes out helpful adults, who deals with it?

The school. At least, it's the school that is going to have to deal with the problems if they're to be dealt with at all. There's no one else. And, over the past ten years, some schools have come to see things just this way.

But word hasn't reached the leafy suburbs (Slaughter teaches at Princeton and presumably sends her boys to Princeton public schools.) Nominally high-performing schools believe it is up to parents to solve school problems. More accurately, nominally high-performing schools believe students don't actually have school problems. Students have student problems, which stem from the student's upbringing and genes and have nothing to do with the school one way or another. *

The problem with this philosophy is that parents can't solve school problems from home, no matter how engaged and well educated and emotionally stable they are themselves. Most obviously, parents can't fix disruptive classroom behavior from home. And while in theory a parent can make sure homework gets done, in practice it's not easy and in some cases it's not possible. (I've seen the not possible scenario firsthand.) Typically, parents have no idea what the homework assignments are or when they're due (echalk notwithstanding), and a parent who has no expertise in a subject can't tell whether her child actually did his or her homework property, or just wrote something down on paper.

As to math, teaching math has got to be the school's job, period. It doesn't matter what emotional problems a student is having; the school has to teach math to struggling students, too.

Affluent schools won't be good schools until they ask themselves Richard DuFour's question: "What will we do when students aren't learning?"Ask, and answer.

the leafy suburbs: School Reform Moves to the Suburbs by Mike Petrilli

* True of the bullying issue, too. Bullying is something kids do, and parents are responsible for kids, so parents need to stop their kids being bullies. Not sure what this means for parents of the child being bullied, of course. 

Thursday, February 23, 2012

can elite students do arithmetic?

Looks like the answer is no. (pdf file)

After a conversation with a "well respected mathematician who was heavily involved with K-12 mathematics education," W. Stephen Wilson re-analyzed the results of the arithmetic test he gave his Calculus III students at Johns Hopkins in 2007. The unnamed mathematician had told Wilson that fewer than 1% of college students would be unable to work a multiplication problem by hand, so Wilson took a look:
He was a little off on his estimate.

In the fall of 2007 I gave a 10 question arithmetic test to my 229 Calculus III (multi-variable calculus) students on the first day of class. Among other things, this means they already had credit for a full year of Calculus. The vast majority of these students were freshmen and ... and the average math SAT score was about 740.

[snip]

Seven of [the problems involving multiplication] were each missed by 8% or more of my students and 69 students, or 30%, missed more than 1 problem.

These are high achieving, highly motivated students (remember the 740 average SAT math score). These are disturbing numbers for them, but I suspect the numbers are much much worse among college freshmen with an average math SAT of 582, and, from Table 145 of Digest of Education Statistics 2009 we see that the average SAT score for the intended college major of engineering is 582 in 2008-2009.

Anyway, there is no real purpose to this paper except as a resource for me. It does suggest, very strongly, to me, that we have lost the pro-arithmetic war. This is a revelation to me and it calls into question what I will do next year with my big service course. I now feel compelled to assume that [my students] are chronically accident prone or they really are arithmetically handicapped. It isn’t clear that there is a difference. The question remains, how can I teach serious college level mathematics to students who are ill-prepared?
For passers-by, here's a quick run-down of Wilson's original observations:
As another experiment, Wilson gave a short test of basic math skills at the start of his Calculus III class in 2007. The results predicted how students later fared on the final exam. Those who could use pencil and paper to do basic multiplication and long division at the beginning of the semester scored better on the final Calc III material. His most startling finding was that 33 out of 236 advanced students didn’t even know how to begin a long division problem.
Back to Basics for the "Division Clueless"
DECEMBER 6, 2010 | BY LISA WATTS

Monday, April 25, 2011

A really bad idea I hadn't heard of

In today's Wall Street Journal:
Assemblywoman Nancy Calhoun, a Republican of Orange County, introduced a measure mandating that school textbooks of all subjects be authored by current or former New York schoolteachers. The bill memo says that such a law would help "provide equal and balanced learning opportunities for K-12 students" and cut down textbook costs by up to 80%.

No Elephant in the Room With These Laws
by Jacob Gershman
APRIL 25, 2011
A law that would actually make it illegal for New York school districts to adopt Singapore Math.

Or any textbook written by an actual mathematician.

Friday, March 4, 2011

corn on the cob

Have been meaning to post this --

A few weeks back David Letterman showed a print ad that reads:
Corn cobs 4 for $1.00
Works out to 25¢ a piece

Saturday, February 20, 2010

math wars

comment left on Numbers Wars: School Battles Heat Up Again in the Traditional versus Reform-Math Debate in the March issue of Scientific American:
Sad but true. I was at a fast food drive thru when the computers were down. They had to make change the old fashioned way. But the girl could not figure out how much change to give me. She seemed lost as she tried to calculate the difference between what I gave her and what the food cost. She had to call in the manger, who took way to long to compute the change (eventually she found a hand-held calculator).

Apparently even simple arithmetic is no longer well taught, learned and/or retained. Reliance on machines to "teach math" is only good if one has a machine when it is needed. My daughter had these classes where the calculator was required. The problem was that after smacking the keyboard a few times, she could come up with an obviously nonsensical answer. She would just write it down and move on. I asked her one time how she could multiple two numbers that each were less than one and come up with an answer that was greater than ten. The blank stare said it all (fyi - she failed to enter the decimal points correctly).

Want to terrify a teen-ager? Ask them to multiply 12 times 12. Is the answer immediate or not? Forget adding simple fractions. And we expect these kids to learn algebra and higher mathematics?

Are kids today less proficient even in arithmetic than in the past? Surely we can tell if these newer teaching methods are getting better results or not. As for me, I think my daughter did better in arithmetic in elementary school. After middle and high school, she seems to have "lost" the ability to easily do the arithmetic she learned earlier in life. I blame the calculator.
Twenty years of reform math.

That's a long time.

Thursday, February 18, 2010

rightwingprof: "I Would Like an Answer Now"

Clay Bond posted this to rightwingprof on March 29, 2006. It's a keeper.

'Yes, I posted this some time ago. However, the questions are not rhetorical. I really would like an answer from my colleagues in the primary and secondary school system — particularly those in the education union establishment. And I’d like an answer because I really do want to know why I have to do your job as well as mine.

Thanks ahead of time for your response. Here it is:

I don’t want anyone to get the wrong idea. I’ve had many extremely bright students. Many. Some had the necessary knowledge for the class, and some did not; of those who did not, most worked their butts off and did well. I also don’t want you to think smarts are what I care most about.

My favorite students are the ones who aren’t that bright, but work their tails off to do as well as they can. My least favorite students are the ones who are extremely sharp, but don’t work.

Sometimes, however, there’s too much missing knowledge, so much that the best thing the student can do is drop the class. It breaks my heart when I get a student like this.

I had a student some time back I’ll call Mark. Mark was bright, though his high school had cheated him, and he was lost almost from the first day. He worked hard, and came to my office hours. But … well, there was too much missing, as I discovered early in the semester when he was in my office.

I asked him what he wanted me to clarify, and he said he didn’t understand the 68-95-99 Rule. The conversation went something like this:

Me: “In a normal distribution, 68% of the data fall within one standard deviation in either direction of the mean. So here’s our distribution,” I drew a bell curve on the whiteboard, “And here’s our mean,” I drew a dashed line bisecting the curve. “Our mean is 50, and our standard deviation is 2, so 68% of the data fall between 50-2 and 50+2, 48 and 52.” I drew lines and arrows, and a 68% beneath.

Mark: “I don’t understand. Wouldn’t it be 75?”

Me: “Wouldn’t what be 75?”

Mark: “The mean.”

Me: “Why would it be 75?”

Mark: “That’s what you said in class.”

Ah. He was stuck on the example — and being a firm believer in introducing concepts in contexts familiar to students, I introduce basic descriptive stats in terms of grades, since what else are students more familiar with?

Me: “The mean could be 75, sure. In this particular distribution,” I pointed to the curve on the whiteboard, “the mean is 50.” I then erased the 50. “But let’s say the mean is 75,” and I wrote 75 after the x-bar, “then 68% of the data falls between 75-2 and 75+2, 73 and 77.”

Mark: “How do you know if the mean is 50 or 75?”

One of the difficult parts of teaching is diagnosing the problem. Students have questions, but the problem may actually be more fundamental than what they are asking about, as I was beginning to understand here.

Mark was having two basic problems: He didn’t understand what a mean was, and he was having trouble abstracting the idea out of the example. The former is easy to fix; the latter is not.

Me: “Can I erase this?” I pointed to the whiteboard, and he nodded. I erased the curve, and wrote a series of numbers on the board in a vertical column: 90, 85, 70, 65, and 50. “These are test scores,” I said, “How do you calcualate the mean, or average?”

Mark didn’t volunteer an answer.

Me: “Okay, let’s say the whole class takes an exam, and these are the scores. An average, or mean, tells me how well the class did overall. To calculate the average, I add all the scores, then divide by the number of scores. Here, you do it.” I have him the marker.

Mark added the numbers, then stopped.

Me: “How many scores are there?”

Mark: “Five.”

Me: “Okay, divide the total by five.”

Mark complied.

Me: “What’s the mean?”

Mark: “Seventy-two.” He looked at the numbers for a minute, then smiled. “I get it!” he said.

That’s when I realized what I’d suspected: Mark was a university freshman who had not, until just now, understood the concept of an average. I found that disturbing, but Mark was on a roll.

Mark: “So what’s a median?”

Me: “The middle score.” I pointed to the five numbers. “Half of the scores will fall above the median, and half will fall below the median. What’s the median of these scores?”

Mark: “Seventy.”

Mark was in my office three hours. No wonder he’d been lost. He didn’t understand an average. He didn’t understand sampling or distributions. We didn’t get to the 68-95-99 rule that day, because there was too much he didn’t understand.

I worked with him twice every week, and he got a B in the class. He worked harder than nearly any other student I’ve had. But if he had not come to my office every chance he got, he would never have passed.

Mark had no sense of entitlement. He wanted to understand, and he wanted a good grade, and he worked for both. He was bright. The thing is, I pretty much ran him through a high school math program in the office during the course of the semester.

I’m a teacher, so I can ask the obvious question, and some other teacher can’t come back with any of the usual non-answers.

I did it. Why couldn’t you, when Mark was in high school? It’s not money. I got no extra pay for helping Mark. It’s not time. I spent many hours in the office working with him. It’s not his intelligence or ability to learn. He’s smart, and he learned quickly, once we got started.

So I’ll ask again: Why couldn’t you do your job? It wasn’t my job to teach Mark high school math, but I did. Why did I have to? How did Mark get through all the required high school math courses without understanding what an average is? How did Mark get through all the required math courses without ever having seen y=mx+b? How did Mark get through all the required math courses and not understand that each flip of the coin is independent of all others? Most of all, how did you, his teachers, let such a bright, hard-working, motivated student slip through the cracks?

What’s going on there?

Thursday, December 17, 2009

links for Barry's Education Next articles

The links to Barry's Education Next articles have gone missing on Google, so here they are (I'll get them linked on the sidebar, too):

An A-maze-ing Approach to Math (2005 and now a classic--)

Miracle Math (about Singapore Math)

I'm giving both articles to folks here.