Education ∪ Math ∪ Technology

Tag: math (page 6 of 10)

Objections to computer based math

At the conference I was at in London, we were discussing, what would a mathematics curriculum look like if the computational step of doing mathematics was something students did using a computer?

Update: The video from this session has been posted by the Computer Based Math organization. See below.

 

Here are some objections shared by Conrad Wolfram and Jon McLoone at the Computer Based Math summit that happened in London, England. I just thought I’d add my two cents, and offer some more possible objections not in this list.

  1. You’ve got to know the basics first.

    First, what are the basics, and why did we define them that way? Are they basic because the concepts are basic, or because they were discovered in a particular order? Are they considered basic because of computational complexity, or because of conceptual complexity?

    Seymour Papert, in his book Mindstorms, suggested that much of what we teach in mathematics classes is the result of historical accidents. He also suggested that we teach some concepts, not because they are the most valuable to teach, but because they can be solved with paper and pencil.

     

  2. Computers dumb math down.

    Jon McLoone has a terrific rebuttal to this argument. His basic premise: we’ve dumbed down mathematics education to limit us to what we are capable of doing with pencil and paper. I’d like to add that we have already turned mathematics education into sitcom-like instruction, where each topic can be taught in a single lesson (or a series of topics can be taught in a single unit), and where older topics are rarely, if ever, revisited. Having taught students how to use a particular topic, we then abandon it to learn new techniques.

     

  3. Hand calculating procedures teach understanding.

    While I think that it possible that hand-calculating can teach something, too often I see people learn recipes for doing math, rather than actually learning mathematical reasoning. I don’t see this procedure necessarily helped by computer based math, but I don’t see that it is hurt either. Whether students do a procedure by hand, or by their computer, if they don’t understand the underlining concepts, they will struggle to use the mathematics in any meaningful context.

     

  4. We’re already doing it.

    Really? There are some small pockets which are using computers as the tool for computation in mathematics, but not on any reasonable scale at the k to 12 level. Students do use calculators, but not consistently across the curriculum, and many potential applications of computers are not well represented by calculators.

     

  5. It isn’t math.

    Here’s a diagram I’ve created to help capture the process of doing math.
    The process of doing mathematics
    The big place in this process where computations happen is in the formulation (and sharing) step shown in the bottom right-hand corner. Note that actually doing the computation, according to this diagram, is only a tiny piece of doing mathematics. If you agree with my premise, that doing mathematics is more than the computations, you might be willing to accept that actually doing the computation step is a tiny piece of the mathematical process. Can we really say that students aren’t doing math if they hand-off that step to their computer?

    Do you think that children often get to do the entire process of math in schools, or are they often stuck at the computation step?

     

  6. You are making people over-reliant on computers.

    I’d like to have students doing more of the mathematical process. Not everything lends itself well to using a computer, and these types of things will still happen in classrooms. Some concepts and ideas are actually not often taught in schools (such as the applications of origami to mathematics) and should be. I want to see students doing more thinking in classes, not less. Mathematics is not entirely in the tool one uses to do computations; most of it happens in the head.

    So rather than seeing people be reliant on computers, I’d like to see some resources available (in the public domain) so that every computation students do on their computers has the "by hand" method carefully catalogged and available for students to use. I’d like to see the computations become part of a toolset, rather than what our students focus on learning.

     

  7. Traditional math is part of our culture.

    I’d love to see mathematical history taught as an option in schools, so as to preserve the culture of mathematical tradition. That being said, culture changes, and we grow and adopt new traditions. For example, almost no one uses quill pens anymore, and it’s certainly not a skill we teach anymore in schools.
     

  8. Good idea – but it can’t be done.

    People have already been teaching mathematics with computers as a tool for computation for a few decades now. I took a course myself in mathematical computation at UBC, and loved it. Rather than saying it cannot happen, since it has happened, we should look to see how we can expand and learn from the current iniatives.
     

Some further objections I can imagine people having:

  1. It isn’t fair; some students have access to technology, some do not.

    This is one objection that I think has some merit behind it. We need to ensure that if we do move toward a model where computers replace the by-hand methods, we need to ensure that everyone has equitable access. As Seymour Papert (and others) have noted, a computer is only a tiny fraction of the total amount of money we spend on a student’s education, and so objections based on money seem to assume that we need to keep all of our existing structures, and that we can’t shrink some of them to pay for computers. How much money do we spend encouraging disengaged learners to remain in schools?

     

  2. It isn’t healthy.

    It’s also not healthy to lack mathematical reasoning, literacy and analytical reasoning skills, but we let plenty of students graduate without these vital skills for life. We do need to balance screen-time versus other forms of more interactive and kinethestic learning, and this will be one of our challenges going forward in education.

     

What are some other objections you can imagine people having to this kind of change in mathematics? Can you extend my rebuttals to these objections?

Math in the real world: Marshmallow constructions

This is another post in my series of posts on math in the real world.

Building materials

My wife, son, and I  went to a kids science event at SFU today, and at one table they had some marshmallow diagrams set up to demonstrate molecules. They let the kids play with the marshmallows and toothpicks, so my son made a giraffe. When we got home, he helped himself to some marshmallows and toothpicks and continued to make things with them.

Simple diagram

 

My son noticed that the most stable form included triangles (with some help from mommy), so he started to construct everything with triangles. When he moved into three dimensions, he noticed that the tetrahedron was the most stable of the forms he could build and so his construction soon began to look very mathematical in shape.

More complicated diagram

 

Now in his most complex form, he has started to build a three dimension tesselation. If he hadn’t been called away to dinner, or if we hadn’t been running low on toothpicks, I’m sure he would have continued the pattern.

Very complicated diagram

 

This activity involves both 2d and 3d geometry, tesselations, sequences and other patterns. Can you think of other mathematics that can be found in this activity?

Should we teach the standard algorithms for arithmetic?

Just posted this comment on this article lamenting the loss of the standard algorithms in Mathematics classrooms.

Should we teach the standard algorithms for arithmetic? Absolutely, but they shouldn’t be the only algorithms kids learn.

Why exactly is the ability to add, subtract, divide and multiply large numbers so critical? It seems clear to me that these are useful skills for numbers we will encounter in our day to day lives, and that it is useful to know that algorithms exist to work with larger numbers, but your other connections seem tenuous to me at best.

You’ve argued that without practice using algorithms, students will not be able to remember them to use them later, and this I agree with. It is a basic tenet of education that spaced repetition helps students remember how to use knowledge.

The question is, what type of knowledge is critical for students to remember? Does knowing how to multiple 39835 by 2338383 or any other arbitrarily large number assist the typical person in their life? Does it even contribute to a greater understanding of advanced mathematics? Has the number of people completing advanced mathematics degrees dropped? Statistics Canada data from 2007 suggests that it has dropped very slightly (see http://www.statcan.gc.ca/pub/81-004-x/2009005/article/11050-eng.htm) but not by an alarming amount.

Regarding your achievements as a PHD in mathematics, don’t forget, the plural of anecdote is not data. You can’t generalize from your one experience to what is useful for all of society.

Understanding how to use the algorithm seems sensible to me, but I think it is even more important that people understand algorithms (emphasis on the plural) which is probably lacking in the current curriculum as it is constructed.

One problem is that all across our society, at many different age groups, we have a lack of people using any advanced mathematical thinking to solve problems. If you look at how people solve problems similar to what they learned in school, but in a different context (see Jean Lave’s work), you find that it is rare for people to use the standard algorithms they learned in life, despite the fact that the standard algorithms are much more efficient than the various algorithms people construct for themselves. This suggests that even though the standard algorithms are more efficient, they may still not be the best algorithms to teach.

It seems to me that if over the course of a lifetime, some knowledge is going to be forgotten, the skill of learning is more important than what specific knowledge is learned.

Update: I’ve had another conversation with the author of the blog post above, and it seems I’ve over-reacted a bit. We have more in common than we disagree about.

Eric Mazur: Memorization or understanding: are we teaching the right thing?

I recommend this talk by Eric Mazur on why he switched his teaching from lecture based teaching to peer instruction based approach. It’s more than an hour long, but it really is worth it.

 

How does this change how we teach? How much of what students learn in our classes is actually learned? If a student can only apply the concepts they have learned to very familiar contexts, and are completely unable to apply them in different contexts, can we really say they have learned the concepts?

I tried the Khan Academy

As an experiment, I started out the beginning of this year and tried flipping my classroom, but with a slight twist: I have extra instructional time, so students were to watch the instructional videos (from the Khan Academy and IBVodcasting.com) during classroom time. We spent about 1/3 of classtime using the Khan Academy videos and exercises, about 1/3 doing problem solving activities (like what is available on www.mathpickle.com and projecteuler.net), and the rest of the time attempting to put the knowledge we were learning into a useful context for the students. While students were involved in these activities, I spent my time circulating the classroom and providing individual and small group support and instruction.

After a month I ended my experiment and am currently in a state of transition while I explore other possible ways of running my classroom. Here are some of the reasons I ended it.

  • Some students chose, despite repeated requests from me, to only watch videos and do exercises that were really easy for them, instead of advancing their knowledge. One student said "she liked the easy videos because it was easy to get points." Another student said she chose the easy exercises because "she was worried about getting problems wrong." These students were more focused on getting easy points and avoiding challenges than learning.
     
  • Some of my students ignored the point system of the Khan Academy and focused on learning, but found that the information from the Khan Academy wasn’t challenging enough. When given practice questions from the course content, they found that the Khan Academy style questions didn’t adequately prepare them. This was partially addressed for these students by switching to the IBVodcasting.com videos, since they are more difficult.
     
  • A few students were able to "master" the content in the Khan Academy exercises after watching a few of the videos, but were unable to transfer what they had learned to any other context, and when queried in more depth, lacked basic understand of what they were learning. For example, they could solve problems like log10 + log2 = log20, but had no idea how to find the value of log20 in terms of p and q when log10 = p and log2 = q.

I’m hoping to implement the RME model and looking for resources that will help support the course curriculum I’m required to cover in the International Baccalaureate program. If I can’t find resources to support this, I’m switching back to my style where I spend some time with students doing experiments in math, some time working on practice problems, and some time with me explaining mathematical concepts. I’m definitely not using the Khan Academy videos again (but I will probably use the IBVodcasting.com videos as additional support for students).

 

See this Slideshare presentation for a description of what the RME model looks like.

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When should we introduce kids to programming?

I recommend listening to this interview of Douglas Rushkoff on CBC Spark by Norah Young.

 

Rushkoff’s recommendation is that children should learn a little bit of a taste of programming right after they learn long division. His reasoning is basically this; once students see an algorithm like long division, and they learn how to make a computer compute long division for them, they’ll see that computers are devices which compute algorithms, not places for them to visit.

I’d like to add that teaching a computer to program something like long division would be very empowering for children. Having been through this process of learning what is one of the most complicated sequences of steps they’ve likely been exposed to in their young lives, they can then conquer this algorithm and "teach" a computer how to do it. As a happy consequence of teaching the computer the algorithm, they’ll probably understand how it works better.

Learning Origami

Origami swan

I started learning origami again this past weekend. So far I’ve built a swan, and a couple of paper airplanes that are more advanced than what I usually make but none of it has been particularly complicated to make. I’ve often thought that origami would be a fun hobby, but that I wouldn’t find much use for it in my teaching.

Today, I watched a TED talk (thanks to @BobbycSmith for sharing it with me today) that definitely changed my mind. Origami is way up there now on my list of things I need to learn.