Education ∪ Math ∪ Technology

Year: 2012 (page 10 of 14)

Research on the effectiveness of real world problems in math education

From the National Mathematics Advisory Council of 2008 final report:

The use of “real-world” contexts to introduce mathematical ideas has been advocated, with the term “real world” being used in varied ways. A synthesis of findings from a small number of high-quality studies indicates that if mathematical ideas are taught using “real-world” contexts, then students’ performance on assessments involving similar “real-world” problems is improved. However, performance on assessments more focused on other aspects of mathematics learning, such as computation, simple word problems, and equation solving, is not improved.

It seems to me that if a real world focus in mathematics makes students more able to use mathematics to solve problems from the real world, then this would make much of the mathematics instruction we do more useful. What exactly is the goal of those simple word problems anyway? Aren’t they an effort to add some context to the learning of computations, so that students are able to use mathematics to solve problems? And if students are going to graduate from school, aren’t the problems they are most likely to face going to come from the real world?

Open-ended problems in elementary school mathematics

I’m hoping to find (or potentially build, given how well my search is going) some open-ended problems appropriate for elementary school math classes. By open-ended problems, I mean problems which:

  • do not have an obvious solution,
  • require some time to figure out,
  • have multiple solutions,
  • may require some assumptions are made by the students,
  • are extendable in some way,
  • require that the solution be explained, rather than a single number given as the answer.

I’ve found that the definition of open-ended problem seems to vary quite a bit, with many sources that I’ve found using free-response or open-response as a synonym for open-ended.

Here’s a sample question (forgive the wording, it may need improvement).

10 tables with 10 chairs

Ellen is planning a party for her friends. She has invited 100 of them, but she doesn’t know exactly how many of her friends will attend. She wants to put out tables for her friends, and she wants to put enough chairs at each table so that none of her friends has to sit alone. Assume that her friends will fill up each table as they arrive. How many tables should she put out, with how many chairs at each table?

 

The curriculum link here is either counting (likely to be a slow technique so I’d recommend reducing the number of friends if this is the strategy your students are going to use), addition, multiplication, or division. Note that if you do questions like this, it is important for students to explain their reasoning, and you may need to help some students do this. You may also have to point out that since Ellen doesn’t know exactly how many of her friends will attend, this problem is harder than it looks. Also, I may or may not give the actual diagram as this likely gives away too much of the problem to students. Once students have drawn a diagram though, one could turn this into a bit of a probability question (given the diagram above, how likely is it that one of Ellen’s friends will have to sit alone?).

Does anyone else know a source of questions which are this open-ended, and are designed for elementary school students? 

 

Update:

Here are some resources I’ve been given or found so far:

No one burns themselves twice

Well, okay, some people do burn themselves twice, but hardly anyone. The message is loud and clear, touch the stove and you get burnt, which hurts. There are lots of other things in life people learn the first time.

I was mouthing off in class one time about how much I hated the school newspaper, when Michelle turned to me and nearly with tears in her eyes said, "Do you really think that, David?" Of course, I was just making noise, and didn’t really mean it, but nothing I could do could fix that moment. I had jammed my foot far into my mouth, and I was not able to back-pedal smoothly. 20 years later, and I can still remember this exact moment. I didn’t need 15 slightly different examples with the answers in the back of the book to remember this moment, and the lesson that came with it.

How can we make more of the learning in school have the same kind of stickiness? Do I remember these lessons because they hurt, or because I had a strong emotion attached to that moment?

First the work, and then the theory

I love this quote shared by Gary Stager via the Daily Papert.

“They first learn engineering, then from there they progress to learning the ideas behind it, and then they learn the mathematics. This would be inventing, it’s a little probe toward inventing a different kind of content. It’s not a different way of teaching; it’s not pedagogy. It’s different knowledge. It’s a good example of turning knowledge – turning learning – upside-down. Instead of starting with this abstract stuff we had from the nineteenth century, let’s start with stuff that’s really engaging for the children, out of which the deeper ideas can develop.” Seymour Papert, 2004

Instead of students learning a bunch of theory, and then being able to apply it to practice, they would engage in building and in creating, which would provide a need and a motivation for the knowledge behind the thing that they are building. One thing that is missing in great degrees from our school is motivation. Why do I need to learn this math when I can see no use for it?

It’s not to say that there aren’t fascinating ideas which are worth learning without something practical to support them, but this is not the general tendency of school. We do not usually teach (with obvious exceptions being good teachers) that which is interesting. We teach practical knowledge. We tend to say, "Oh, we’d like kids to be able to be doctors. Well, what do they need to know? Let’s teach them that." with the result that students do not see the connection between what we teach, and what they can do with it.

Learning mathematical ideas through literature

I looked through our school library today to see if we had any books which would tell mathematical narratives, and I found the following collection. Some of these stories are more "mathy" than others, but each of them has a narrative written around a mathematical concept. Some of these stories could be used to develop context for your students.

 

Anno’s Mysterious Multiplying Jar

This short book tells a very interesting story about a mysterious land with 2 countries, 3 mountains inside each country, and 4 kingdoms inside those countries, and so on, ending with 10 jars. The first pages are essentially describing what a factorial looks like, and if the story ended with question "how many jars are on the island?" I think it would have been an excellent lesson hook into factorials. Unfortunately, the book continues after describing this very interesting narrative with a fairly complete description of factorials. If you are a home-schooling parent, and you want to understand factorials better, and have a story to share with your students, this could be a fabulous resource. If you are a teacher, I recommend ending the story on the page where it first asks how many jars are in the boxes (read the story), and using this as an introductory activity with your students into factorials. Alternatively, this could be an interesting lead up to a less interesting arithmetic problem, wherein the students actually calculate how many jars there are.

 

The Number Devil

This is a novel about a boy who has a fantastic series of dreams full of interesting mathematical ideas, described in language he understands by a character called the Number Devil. The ideas in this story are very interesting to me as a mathematics teacher, and although I’m not sure every kid would enjoy this story, certainly those kids (and adults!) who are interested in mathematical ideas would find this story very interesting. Teachers may also find this book a useful resource for analogies and narratives to help students understand some complicated mathematical concepts. Disclaimer: I have not yet read this entire book, but have enjoyed the 1/3 of it or so that I have read.

 

The Fly on the Ceiling

This story is a historical account of how Rene Descartes may have come up with the idea of the Cartesian plane. According to some other sources I consulted, unfortunately the story is either not true, or incomplete, as it somewhat ignores the series of other inventions made by other mathematicians in advance of Descartes. That being said, it does have an excellent description of how one might make their own Cartesian plane, and teachers may find some inspiration for activities related to introducing the Cartesian plane from this book.

 

A remainder of one

This short story is an excellent description of remainders when doing division, and presents an interesting puzzle. How can 25 soldiers be divided into rows evenly with no remainders left over? One could easily find other such puzzles that are related, and make the concept of remainders much more tangible for students. I think that students may find this book interesting (even younger readers who have not yet learned about division) as well as parents and teachers looking for a lesson idea.

 

Sir Cumference and the Great Knight of Angleland

This story is an attempt to justify the use of angles to solve a problem of navigating through a maze. In terms of giving students some context for understanding angles, I think it does an okay job. One of the benefits of this book is that it does not show the same angles using exactly the same diagrams, which may help students understand that just because two angles have different size rays (or line segments) attached to them, they may still be the same size. I think some students will enjoy this, and teachers may find some useful activities for students to do related to the concept of angles.

 

One Hundred Angry Ants

One hundred angry ants is a short story about 100 ants trying to get to a picnic quickly, and trying different arrangements of rows of ants and the number of ants in each row. The story is appropriate for talking about factors of 100, and could be easily turned into a problem about factors of other numbers. Students will probably find this story interesting up until about 7 or 8, but teachers may find it a source of an idea about teaching that some numbers have multiple factors.

 

Among the Odds and Evens

This short story describes what happens when X and Y visit the land of the numbers. They find to their surprise that there is some strange relationship between the oddness or evenness of the parents, and their offspring. I think this book is interesting to help children remember the fact that odd numbers when added together always add up to an even number, and that even numbers always add up to be even, and that an odd and an even number add up to be odd. However, I suspect that this will be more interesting to student to discover this relationship between numbers (among the many other relationships out there).

 

One Grain of Rice

This is a retelling of the classic story where a peasant outwits the ruler of the land by asking for a doubling reward each day, and ends up with a much larger reward than the ruler expected. It would be good for introducing exponential growth. I would recommend stopping through the story occasionally and asking for predictions from the students about how good a deal the Raja gets. There is an interesting follow-up question for the students as well which is somewhat open-ended: how many years has the Raja been collecting rice? Is it possible for him to have collected 1 billion grains from the lands in his kingdom?

 

Two of Everything

In this story, an old woman and her husband discover a magical pot that allows them to double everything. It could lead to some interesting questions, like "how long will it take the couple to gain enough money from their pot to be comfortable for the rest of their lives?" I’d recommend this for parents who would like to develop more number sense in their children, and for teachers who would like a hook for a lesson around symmetry, doubling, or multiplication.


The Phantom Tollbooth

This book is a treasure trove of logical puzzles, mathematical ideas, and will get kids thinking about different ways of viewing the world. I remember reading it when I was a kid, and I thought it was excellent. Years later, I realized just how many mathematical ideas were in the book. I would recommend this as reading material for students, parents, and teachers.

 

If you know of more books like this, which have a mathematical concept (more interesting than counting books please, there are SO many of those) embedded within the storyline in some way, please share them.

Update: I saw this huge list of books with mathematical ideas shared via Twitter. No reviews, but each book has a very short word description of the math idea to which it links.

On incentives in the teaching profession

So I read some interesting research on student incentive progams which has a couple of very important paragraphs. Here’s the abstract:

This paper describes a series of school-based randomized trials in over 250 urban schools designed to test the impact of financial incentives on student achievement. In stark contrast to simple economic models, our results suggest that student incentives increase achievement when the rewards are given for inputs to the educational production function, but incentives tied to output are not effective. Relative to popular education reforms of the past few decades, student incentives based on inputs produce similar gains in achievement at lower costs. Qualitative data suggest that incentives for inputs may be more effective because students do not know the educational production function, and thus have little clue how to turn their excitement about rewards into achievement. Several other models, including lack of self-control, complementary inputs in production, or the unpredictability of outputs, are also consistent with the experimental data.

Notice the sentence in bold. Incentives for outputs (like let’s say student test scores) does not improve performance. Incentive for inputs (like increased collaboration, more training, working in high needs schools) does. Of course, the benefits gained by the incentives are not terribly strong (with the exception in the study of students being paid to read more) and so any benefit from paying teachers for changing the inputs to education may be minimal.

The merit pay for teachers movement has it all wrong, and the very people in promoting merit pay for teachers have access to this research. In fact, the list of acknowledgements at the beginning of the paper is a veritable who’s who of the leading education reformers in the US.

Converting degrees to radians

One of my students came up (with some help) this procedure for converting between degrees and radians.

  1. Memorize the fact that 60° is π/3 and that 30° is π/6.
  2. Note that 10° is therefore π/18 and that similarly 1° is π/180.
  3. You can then take any degree measure and convert it by converting the number of degrees into sums of degrees where you know the conversions. For example, 70° is equal to 60° + 10° = π/3 + π/18 = 6π/18 + π/18 = 7π/18.

Obviously this procedure is not by any means the most efficient way to convert between radians and degrees. Although I showed a much more efficient algorithm for converting between degrees and radians, it didn’t make sense for this student, and so he and I came up with this procedure (which I drew out of him by asking him questions about the angles), which he does understand.

In general, I’d prefer students use inefficient techniques that they understand completely than highly efficient techniques that they do not understand. Hopefully this student will continue to work on his procedure to make it more efficient as he has to use it over and over again, but if not, at least he will be thinking with something that makes more sense in his head.

Automaticity in programming and math

I’ve been learning how to program for a long time, a task that has much in common with mathematics. Both programming and mathematics involve being able to solve problems. Some of the problems in programming and mathematics have well established solutions and other problems do not. On a micro-level, programming involves manipulating code, a task much like the symbolic manipulation often used in mathematics. On a macro-level, programmers and mathematicians both need to be able to trouble-shoot, organize, and communicate their solutions.

Sample code:

Sample code

When I learned how to program, I taught myself, and I know that as a result, the code I create does not always follow the most appropriate industry standards. I have some unconventional solutions to some of the standard problems in programming, and I have less than optimal solutions for some basic problems in programming. I’ve yet to develop my own library of solutions, a standard practice in the industry.

On the other hand, I’m not a professional programmer. I program to solve problems I run into in life, and I program for fun. I have many programming projects that I’ve started and not completed. I’m an amateur programmer. I don’t need my work to look exactly what professional programmers’ work looks like because I rarely, if ever, share my programming with other people. I often share the results of my programming though, and this has helped build some useful tools for my students.

There are many low-level tasks that I no longer need to reference. I don’t need to look up how to define variables or functions, and I don’t need to look up loops, conditionals, and other basic parts of the structure of the programming languages that I know. I still need to look up the methods and properties of some higher level objects in the programming languages I know though, and when I program in PHP, I have a reference manual for the hundreds of functions available in PHP always open. I could be said to have developed a certain amount of automaticity in learning how to program, especially for the more basic tasks.

This automaticity was not learned by memorizing programming structures. I didn’t develop automaticity by doing practice exercises. I didn’t develop automaticity by reading books on programming. I developed automaticity in the low-level programming tasks by programming, by giving myself projects to work on that required me to build my skill, and by repeatedly looking up reference material when I got stuck. I developed automaticity because it is frustrating to write code that doesn’t work. It’s frustrating to get error messages that are nearly incomprehensible back from the computer when you make a mistake in the structure of your code.

If we look at mathematics education, we see that many, many of the problems given to students which have standard solutions. We expect students to develop fluency in these problems, often before they ever get to see any of the non-standard problems. In fact, in k to 12 education, students can potentially never be given an open-ended non-standard problem. Unfortunately, I believe this approach has failed our students in the past, and I’m not alone.

I’d like to see a system without a focus on fluency and automaticity in mathematics. These are the wrong drivers of mathematics education. Instead of focusing on the lowest level tasks mathematicians do, and assuming that fluency in these tasks leads to mathematical reasoning, we should focus on the most interesting and challenging tasks, and expect that a certain degree of fluency and automaticity will be developed as a result of these tasks. Instead of expecting students to memorize recipes and algorithms, we should allow them to develop toolkits and libraries to use of their own that they can reference as needed. Instead of feeling that every problem students need to do has to be solved quickly or efficiently, we should allow for alternate solutions and methods to be used.

The next big thing

Stephen Downes shared this article about the next big thing in network analysis. He writes:

Valdis Krebs argues that the next big thing in network analysis will focus on the contents of what we read (and not just the titles as entities) in order to draw connections between people. It’s a natural evolution of network analysis. "It is not just the also-bought data that matters (which books bought by same customer), it is what we specifically find interesting and useful in those books that reveals deep similarities between people — the hi-lites, bookmarks and the notes will be the connectors. Our choices reveal who we are, and who we are like!"

I’m going to argue that what would be even more valuable than a better way to determine who is most similar to us would be what important ideas do we not know, and perhaps we should. We have this crazy amount of data on what people read, what videos they watch, and who they chat with, which should in theory be able to help determine what "important" things they have not yet read, and even some of what they do not know. We should be able to use network analysis to direct learners into new learning experiences.

This is similar to the Netflix (and Amazon, etc…) recommendation engines, which suggest similar titles to what one has experienced already. Unfortunately this approach leads us isolated in a bubble. Instead, what if these recommendation engines looked at what was in our circles, and found something important to know that is perhaps an opposing point of view, or a different perspective on what we know. I’d happily sign up for a service that culled the best of the opposing ideas to my own perspectives and shared those new perspectives with me.

Instead of finding better ways of leading people to re-inforce existing knowledge, can we find better ways to direct them at new ideas?

 

Fixing audio from a video track

The problem:

Our students had recorded video of themselves, but the audio from the video was too quiet to hear. Unfortunately, they had recorded their video on a Flip camera from a distance of 7 or 8 metres in a large open space, and forgot (or did not know) that this would result in extremely poor audio.

 

A solution:

We don’t have the kind of video editing software readily available for students that would fix this kind of problem (I think our film course has access to Final Cut Pro), so I wanted to find a free solution for fixing this audio.

I found WinFF, which is an open source video conversion tool, which happily converts from a video to audio, essentially isolating the audio from a video file. I downloaded it, and installed it to my computer. After some experimentation, which I did with the students, I discovered that the following settings worked best for this process.

WinFF

 

I then imported this audio into Audacity, and used the volume adjustment option (see below) to increase the volume of the audio track of the video.

Audacity

 

Once the audio volume was adjusted, I then imported the video and the new audio track into Windows Live Movie Maker, where we muted the original video, and used the new enhanced audio track. Queue the excited students who no longer have to re-record their video!

 

The follow-up problem:

This is essentially a magic tech recipe that the students may be able to reproduce, but I doubt they will be much better at trouble-shooting their own tech problems in the future. As I outlined the solution for the small group of students I was working with, some of them were interested, others were not. They displayed many of the signs I see when I see math taught the wrong way. They have no idea what the OGG audio format is, or why it would be the best choice to work with Audacity.

 

Questions:

  1. How can we make learning technology more seamless? I see technology as a tool for other activities, but some of our current technologies are so difficult to work with that something which should be simple (increasing volume of a video) is difficult.
     
  2. Is is better not to help these students in the long run when the task they want to do is beyond their current technology skills? Is there a reasonable balance we should strike between assisting students finishing the project today, and helping students become more independent tomorrow?
     
  3. How is this related to mathematics education today? How often do we help students solve fabulous open-ended problems with magical mathematics techniques they don’t really understand?