Posted in What is mathematics

Art and Mathematics

This post is actually one of the comments in my Mathematics is an Art post. I thought it would be a waste to just leave it in the comments section. It’s very informative and well written so I’m sharing it here. That way more people will have a chance to read it. It’s from the writer of one of my favorite blog Research in Practice, mr. benblumsmith. Here’s what he says about mathematics and art.

I want to add three defining characteristics (to me they are the defining characteristics) to the definition of art that you are constructing. I think all three help illuminate why math can be an art. I’m basing the choice of these characteristics on my own experience as a musician. Other artists might have other definitions, but actually I speculate that these are pretty commonly held as important characteristics of art.

1) Art is creative and expressive.

All the arts are about making things. Songs, paintings, plays, performances, etc. Crafts and industry are also about making things, but what distinguishes art is that the act of creation is an act of expression for the person doing the creating. Creating the painting, playing the sonata, singing the song, etc. are all ways of taking a part of yourself and giving it to others.

(Why math is creative and expressive: every time you figure out how to solve a problem you’ve never solved before, or how to prove a conjecture you have, you’ve made something new that expresses how your mind works to others.)

2) Art engages the imagination.

All the arts stimulate you to see, hear, feel things that aren’t part of the material world. You read a novel or see a movie and you imagine the world it creates. You hear a symphony and you may visualize all kinds of things, or you may just feel them. Either way, your mind and spirit are sent off in totally new directions.

(Why math engages the imagination: if not for math, would I ever have tried to visualize a 4-dimensional torus? The Riemann surface of the sine function? The real projective plane? The strange images in my head that I use to visualize concepts like exact sequences or field automorphisms?)

3) Art is driven by aesthetics.

Artists try to make their creations aesthetically captivating: beautiful, haunting, winsome, grotesque, tragic, delightful, etc.

(Why this applies to math: it’s different for every math person but we all have a sense of aesthetics – what makes math beautiful. For me and for many, a simple argument that proves a powerful result is elegant, for example Euclid’s proof of the infinitude of the primes. Even more beautiful is a theorem that describes a deep connection between apparently very different mathematical realms. For example the Pythagorean theorem as it connects “right anglyness” with “sum of sqaresiness,” the Fundamental theorem of Calculus as it connects “speed” with “area,” or Galois theory as it connects “groups” and “field extensions.”)

Two semi-classic pieces of writing on math as an art that you might find add to this conversation –

Paul Lockhart’s A Mathematician’s Lament.

G. H. Hardy’s A MathematiciansApology.

Both Lockhart and especially Hardy aggravate me (Lockhart with his blanket disdain for math educators and Hardy with his attitude that mathematical talent is an intrinsic attribute that declines with age), but both write eloquently and passionately about how math is a creative art.

Don’t forget to click the links he recommended. Very good read indeed.

Posted in Curriculum Reform

(Mis) Understanding by Design

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The country’s schools are now implementing ‘Understanding by Design (UbD) curriculum.’ Some private schools are implementing it at all levels while all the public schools are on its first year of implementation starting with first year high school subjects. I’m not a fan of UbD, especially in the way it is being implemented here but that is irrelevant. (If I have my way, I rather spend the money for Lesson Study.) But of course, I want UbD to work because DepEd is spending taxpayers money for it. But from conversations and interviews with teachers and looking at what they call call ‘Ubidized learning plans’, I am starting to doubt whether or not what we are implementing is really UbD. Here’s how UbD is understood and being carried out in some schools:

1. With UbD teachers will no longer make lesson plans. They will be provided with one. Here’s a comment on my post Curriculum Change and Understanding by Design: What are they solving? from a Canadian educator:

UbD may not be your priority–I gather that you see PCK and CK as the core issue. But at least UbD positions teachers as the decision-makers rather than imposing lessons on them…. I am not a UbD proponent, but I think it’s a structure I could work with, a structure I could infuse with my beliefs and goals, because it puts teachers at the center of the decision making, with student understanding as the target.

Indeed, nowhere in the UbD book of McTighe and Wiggins that they propose that teachers should no longer make lesson plans or that it is a good idea that somebody else should make lesson plans for the teachers. What they propose is a different way of designing or planning the lesson – the backward design. Continue reading “(Mis) Understanding by Design”

Posted in Algebra

Teaching irrational numbers – break it to me gently

Numbers generally emerged from the practical need to express measurement. From counting numbers to whole numbers, to the set of integers, and to the rational numbers, we have always been able to use numbers to express measures. Up to the set of rational numbers, mathematics is practical, numbers are useful and easy to make sense of. But what about the irrational numbers? You can tell by the name how it shook the rational mind of the early Greeks.


www.wombat.com

Unlike rationals that emerged out of practical need, irrational numbers emerged out of theoretical need of mathematics for logical consistency. It could therefore be a little hard for students to make sense of and hard for teachers to teach. Surds, \pi, and e are not only difficult to work with, they are also difficult to understand conceptually.

It is not surprising that some textbooks, teaching guides, and lesson plans uses the following stunts to introduce irrational numbers:

After discussing how terminating decimal numbers and repeating decimal numbers are rational, you can then announce that the NON-repeating NON-terminating decimal numbers are exactly the IRRATIONAL NUMBERS.

What’s wrong with this? Nothing, except that it doesn’t make sense to students. It assumes that students understand the real number system and that the set of real numbers can be divided into two sets – rational and irrational. But, students have yet to learn these.

Some start with definitions:

Rational numbers are all numbers of the form  \frac{p}{q} where p and q are integers and q \neq 0. Irrational numbers are all the numbers that cannot be expressed in the form of \frac{p}{q} where p and q are integers.

How would we convince a student that there is indeed a number that cannot be expressed as a quotient of two integers or that there is a number that cannot be divided by another number not equal to zero? It’s not a very good idea but even if we tell them that \sqrt{2} is an irrational number, how do we show them that it fits the definition without resorting to indirect proof or proof of impossibility? What I am saying here is it is not pedagogically sound to start with definitions because definitions are already abstraction of the concept. I would say the same for all other mathematical concepts.

Before introducing irrational numbers, students should be given tasks that raises the possibility of the existence of a number other than rational numbers. Another way is to let them realize that the set of rational numbers cannot represent the measures of all line segments. Tasks that would help them get a sense of infinitude of numbers will also help. The idea is to prepare the garden well before planting. Read my post on why I think it is bad practice to teach a mathematical concept via its definition.

Posted in Assessment, High school mathematics

Conference on Assessing Learning

The conference is open to high school mathematics and science teachers, department heads and coordinators, supervisors, tertiary and graduate students and lecturers, researchers, and curriculum developers in science and mathematics.

http://www.upd.edu.ph/~ismed/icsme2010/index.html

Plenary  Topics and Speakers

1. The Relationship between Classroom Tasks, Students’ Engagement, and Assessing Learning by Dr. Peter Sullivan

2. Assessment for Learning: Practice, Pupils and Preservice Teachers by Dr. Beverly Cooper

3. The Heart of Mathematics Teaching and Learning: Assessment and Problem Solving by Dr. Allan White

4. Assessing the Unassessable: Students’ and Teachers’ Understanding of Nature of Science by Dr. Fouad Abd Khalic

5. Lesson Study in Japan: How it Develops Critical Thinking Skills by Prof Takuya Baba

6. Classroom Assessment Affective and Cognitive Domains by Dr. Masami Isoda

7. Assessment cum Curriculum Innovations by Dr. Ma. Victoria Carpio-Bernido

8. Strategies for teaching Mathematics to classes with Diverse Interests and Achievement – Having Problems with Problem Solving? by Dr. Peter Sullivan

9. Assessing Learners’ Understandings of Nature of Science – The New Zealand Science Hub by Dr. Beverly Cooper.

Aside from parallel paper presentations and workshops, there will also be parallel case presentations by science and mathematics teachers involve in Collaborative Lesson Research and Development (CLRD) Project of UP NISMED. CLRD is the Philippine version of Lesson Study.

Clickhere for conference and registration details.