Jumat, 27 Maret 2009

Elementary math & reasoning skills

Someone recently sent me a VERY interesting link:
The Story of an Experiment

Photo by foundphotoslj

This experiment in math teaching was done in the 1930s by by L. P. Benezet, and the main gist of it was that formal arithmetic studies were delayed until the latter half of 6th grade. Instead, the instruction concentrated on "teaching the children to read, to reason, and to recite - my new Three R's."

They also were taught about numbers they encountered in their reading materials, about time, about measuring units, estimation, and coins. Finally in 5th and 6th grade they also learn skip-counting. Formal arithmetic, meaning paper-and pencil work with addition, subtraction, multiplication, and division using a textbook began in latter half of 6th grade and continued till 8th grade.

The experiment was a huge success. Mr. Benezet compared the children's abilities in the experimental classroom to those of the traditional classrooms, and every time the "experimental" children were able to reason out word problems correctly, whereas those taught traditionally just stumbled all around, trying to find some formula to use.

Maria's comments

I find this story very interesting and I've read it before. I can't say that approach wouldn't work better than "traditional math" even in today's world. Maybe it would! Those kids were taught to reason AND they were also taught some basic math skills, just without the use of mechanical formulas. So, they learned to think and reason it in their heads.

My guess is that such an approach would be even better if it was accompanied with some, what you might call, formal, instruction in math, BUT very much avoiding the idea that you use some formula that the teacher gives you "on a platter".

For example, in the experiment the kids were supposed to learn the numbers they saw in books and learn the page numbers such as 76 and 293. But, I wonder if this would have resulted in quicker/better understanding of number system had they been taught explicitly about hundreds, tens, and ones (the place value). Then again, we don't know how exactly the teachers explained those- maybe they did explain them in a very good way.

One of my instructors in university often mentioned the idea of school math being "announcement math" or "announced math". It's announced from a higher authority, without giving kids much in the way of justification, or the opportunity to find the truths themselves and thereby understand them deeper.

I do try to avoid that in the elementary part of math. In fraction studies, I refrain from giving "formulas" for fraction addition or division or simplification until kids have had a lot of experience with "doing" it with the fraction pictures. And even then the formula can be like a "sideline" that is mentioned in passing. I don't want to even deal with LCMs and GCFs when it comes to fraction math in elementary grades.

In general I always try to justify the math and let children experience and understand it on a conceptual level.

As regards to the experiment, they wanted kids to learn reasoning by the usage of good books and reading a lot. Then, when their brains were trained to a certain point, arithmetic was studied from books.

Reading a lot of books and learning reasoning is definitely a good way to go. But, I feel that mathematics, when taught right, can also have a part in this "training the mind" process and learning reasoning. It is very well suited to that if it is taught well during the elementary years - having the emphasis on thinking skills and concepts, not just memorizing formulas.

Rabu, 25 Maret 2009

The Best and Worst Jobs

You might find this interesting: in a study ranking the best and worst occupations in the US, guess where mathematicians landed!

#1.

The study was looking at job hazards, pay, stress levels, environment, and a few other factors. Take a look at it here: Doing the Math to Find the Good Jobs.

Now, this study didn't take into account an individual's likes and preferences and feelings ... If someone REALLY loves cutting timber in a forest, then obviously that's a perfect job for them. But it's still interesting to note that mathematician, statistician, biologist, software engineer, and other "thinking" jobs ranked very high.

Sabtu, 21 Maret 2009

Division of fractions conceptually

I've managed to make another video on a very important topic (I feel) of fraction division. I apologize for the audio; I do want to improve and we will definitely work on that to get it better next time.


Division of Fractions Taught Conceptually, part 1


Division of Fractions Taught Conceptually, part 2

The two parts of the video show a step-by-step approach for teaching division of fractions conceptually:

  1. Start with sharing divisions that divide evenly. For example, 4/7 ÷ 2 can be thought of as "Two people share 4/7 of a pie evenly. How much of the pie does each person get?"

    Children can figure these out mentally without using any rule.


  2. Continue to measurement divisions where we think, "How many times does the divisor fit into the dividend?". Again, the problems should first be designed so that the divisions are even. For example, 4 ÷ (1/2) means "How many times does 1/2 fit into 4?" Or, 3 1/5 ÷ 2/5 means "How many times does 2/5 fit into 3 1/5?" Again, no rule is necessary to solve these - just logical thinking.


  3. Next, study measurement divisions with the dividend of one. This leads to the concept of reciprocal numbers. For example, 1 ÷ 3/4 is thought of as "How many times does 3/4 fit into 1?" As I show in the video, and you should show visually, 3/4 fits into 3/4 once, and into the leftover piece of 1/4 it fits 1/3 of the way. So, all total 3/4 fits into 1 exactly 1 1/3 times.

    Students should do a sufficient number of these kinds of problems so that they get familiar with the thinking process. After that, take some of the problems they have solved, and write the answers as fractions instead of mixed numbers. For example we found above that 1 ÷ 3/4 = 1 1/3. Write 1 1/3 as a fraction, and you get 1 ÷ 3/4 = 4/3. Now, 3/4 and 4/3 are reciprocal numbers. If you multiply them, you get 1. And this happens with every such division problem.


  4. Lastly, we apply this neat pattern with reciprocal numbers to arbitrary fraction division problems, and thus arrive at the shortcut for fraction division.

    For example, 7 ÷ (4/5). Use the helping problem of 1 ÷ (4/5) = 5/4. Since 4/5 fits into 1 exactly 5/4 times, it fits into 7 exactly seven times that many times, or 7 × 5/4 = 8 3/4 times. Similarly, let's consider 6/7 ÷ (3/4). First look at the helping problem 1 ÷ (3/4) = 4/3. Since 3/4 fits into 1 exactly 4/3 times, it fits into 6/7 exactly 6/7 that many times. The answer is therefore 6/7 × 4/3 = 24/21 = 1 1/7.

    We can notice that for any fraction division problem, we end up multiplying the dividend by the reciprocal of the divisor! Students can actually notice and understand this shortcut on their own, using this method. It is no longer just a rule handed to them on a platter as, "Swallow this, no questions." It becomes a concept they can understand.


Selasa, 17 Maret 2009

Introducing Make It Real Learning workbooks

I have recently had the pleasure to add Make It Real Learning workbooks to my site. These books contain real-life math activities with real-life data, companies, and situations. They are written by Frank Wilson.

Some examples of the topics included in these activities are: cell phone plans, autism, population growth, cooking, borrowing money, credit cards, life spans, population growth, and music downloads. But there are many more, more than I can list here.

As students work through the problems, they can use the math skills and concepts they have learned in their math curriculum (such as the concept of average or graphing), and apply those to a situation from real life.

Each activity-lesson in the book contains several questions about the situation, starting with basics and going into more in-depth evaluations, and should be adequate for one-two complete class periods.

Why does that benefit you, the teacher? It will motivate the students far more than dull, boring word problems from the textbook. It will show students how mathematics is truly USEFUL. Also:
  • The problems are written by an experienced math teacher (Frank Wilson)

  • The problems are matched to the learning objectives of the National Council of Teachers of Mathematics (NCTM). This means that the concepts and skills required to complete the problems ARE found in typical middle and high school mathematics curriculum. You can simply replace some of the problems in your textbook with these real-life scenarios.

  • These activities are excellent to be used in a small-group setting.

  • Typically, the activities contain challenging parts and therefore allow students to practice real problem solving - not just apply knowledge from textbook examples to other almost identical problems.

  • Gifted students can enjoy the challenge of solving all the questions on their own.

All books include complete solutions to all activities and problems. Please note that Make It Real Learning workbooks do not contain the instruction or explanations of the concepts.

List of available books:

Arithmetic I - for grades 3-6
Fractions, Percents, and Decimals I - for grades 4-8
Fractions, Percents, and Decimals II - for grades 6-11
Sets, Probability, and Statistics I - for grades 6-10

Linear Functions I - for algebra 1 and algebra 2
Linear Functions II - for algebra 1 and algebra 2
Quadratic Functions I - for algebra 1 and algebra 2

Exponential and Logarithmic Functions I
- for algebra 2/precalculus
Periodic and Piecewise Functions I
- for algebra 2/precalculus
Polynomial, Power, Logistic, and Rational Functions I
- for algebra 2/precalculus
Calculus I - for grade 12

Sabtu, 14 Maret 2009

Free webinar - Math, Science, and Real Books

I just saw this on the LivingMathForum Yahoo Group, and some of you might be interested in it. I'm not sure if I'll make it there, but it sounds interesting.

I will copy the info about it below


Math, Science, and Real Books Webinar

http://homeschoolconnections.webex.com -- then click on Bringing Joy to Your Homeschool Math and Science Lessons

Session date: Wednesday, April 1, 2009

Starting time: 7:30 pm, Central Daylight Time (Chicago, GMT-05:00)

Duration: 1 hour 30 minutes

Presenters: Maureen Wittmann

Description: Literature isn't just for reading! You can teach math, science, language arts, and more using living books. This is the third in a series of three talks on the topic of teaching through real books.

Have you ever said out loud, "I hate math!" Or, "Math was my worst subject!" Was science always a tough subject for you? Do you struggle wondering how you can bring the fullness of the subject to your children? If so, you've come to the right place.

In this talk Maureen will show you how to let go of your math and science phobia and keep from passing it onto your children. Math can be fun and interesting. Really. You just need to look at it in a new light. Science can go beyond the kitchen experiments and come alive in a child's imagination. Really.

Maureen will bring lots of books with her for show and tell. You'll leave this online seminar loaded with book titles, fresh ideas, and practical tips. You won't want to miss it!

Maureen is the author of For the Love of Literature: Teaching Core Subjects Through Literature published by Ecce Homo Press, available from your favorite bookseller or maureenwittmann.com. She is also coeditor and contributing author to The Catholic Homeschool Companion (Sophia Institute Press) and A Catholic Homeschool Treasury (Ignatius Press). Her articles have appeared in Our Sunday Visitor, Homeschooling Today, Heart and Mind, Catholic Digest, and more.

Mrs. Wittmann and her husband Rob are parents to seven children, who have always been homeschooled. She brings to our conference not only her experience, but an excitement and love of homeschooling.



If you're not familiar with webinars -- they're very fun. If you have high speed Internet and speakers then you're good to go. For the math and science webinar, you'll see and hear the speaker just as if she was speaking at a live conference. The difference is that it is interactive. There is a chat room where you can type questions and comments.

If you have dial up or can't make it to the live event, then you could download the recorded event later to watch at your convenience,
http://tinyurl.com/pasthomeschoolwebinars

Jumat, 13 Maret 2009

New design for MathMammoth.com

This new website design is by Cenango.com
Click the image to enter MathMammoth.com.

MathMammoth.com website screenshot

Rabu, 11 Maret 2009

Math Mammoth Clock book free download



CurrClick is offering my title, "Math Mammoth Clock", this week as a free download. If interested, head there, register with them if you haven't already, and get it!

Remember, it is only this week. They are celebrating The Ebook Week, and specifically wished to have one of my titles on the front page.

Senin, 09 Maret 2009

Pi Day

π Day (Pi Day) is upon us soon (on 3/14 or March 14). If you'd like to prepare for it and have some activities for your children/students, check these resources.

If your students don't yet know what Pi is, start with the basics: it is very fitting to explain and discover pi on Pi Day.

Here's a Pi webquest for older students who can search the Internet and encyclopedias on their own. The "Historian" in the webquest has to find answers to some questions, while the "Pi Maker" needs to make an edible model that shows the parts of a circle necessary in finding the value of pi.

BrainPop has a movie about Pi.

Remember also that 22/7 is a great fractional approximation to Pi. This means that if 7 pepperonis nicely fit in the diameter of a pizza, then 22 nicely fit to go around.

diameter of a pizza with 7 pepperonis circumference of a pizza with 22 pepperonis
(From Exploratorium.edu Pi posters)


Find where your birthday is in Pi - e.g. if your birthday is March 14, 1971, find where in Pi's digits is the sequence 31471. (Mine wasn't anywhere in the digits it searched.)

You can read how other teachers have celebrated Pi day. Lots of them use pies - mmmm!

2009 21st Annual Pi Day Celebration page is a good place to spend some time on Pi day or otherwise. You can see read history of Pi, see previous Pi Day images, read Pi limericks, download Pi posters and so on.

Then once you are done with that and STILL have appetite for more, go explore tons more Pi stuff at the links found here.

Sabtu, 07 Maret 2009

Carnival picks

I have a collection of interesting links for you today; mostly some picks from Math Teachers At Play #2 blog carnival, which you SHOULD visit. Denise always has good stuff and really nice photos to spice up the reading.

Here's a neat way to practice multiplication tables by Math Mojo.

I also liked some simple dissection puzzles; you'll even get a free worksheet download.

Nick has posted two geometry "Wrapper" problems

This one is hilarious - lots of pictures of mathematical clocks!

Those were all from the carnival; please check out all the other posts as well; it is a good carnival!

Lastly, I visited this yesterday, and I think ALL of us should check out what a trillion dollars looks like.

Kamis, 05 Maret 2009

Credit crisis video

I thought some of you might enjoy this video about the credit crisis. It's visually very well made.


The Crisis of Credit Visualized from Jonathan Jarvis on Vimeo.


This video is also available on YouTube in two parts: Credit Crisis Part 1 and Credit Crisis Part 2.

Selasa, 03 Maret 2009

It's square root day

Today - 3/3/09 - happens to be a square root day! It's because 3 is the square root of 9 (3 × 3 = 9). The previous square root day was 2/2/04. And then next one is 4/4/16.

An exercise for students: how many square root days are there in a century?
See Wikipedia for an answer..

Read also how the teacher Ron Gordon celebrates square root day!

Minggu, 01 Maret 2009

Fractions to decimals calculator

This is the COOLEST fractions to decimals calculator I've seen! It will convert a fraction into a decimal to any number of decimal places, and TELL you if it is a recurring decimal, and how many digits its period is.

I tried 2/10392, and it said "2/10392=1/5196 has 2 initial digits followed by a period of 432 digits." I won't copy the actual digits here...

Hat Tip goes to MathNotations Blog.