# The IntMath Newsletter - June 2007

By Murray Bourne, 15 Jun 2007

You are receiving the IntMath Newsletter either because you signed up, asked a question, wrote a comment or complimented

Interactive Mathematics.

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1. This month's math tip

2. Apology for name inclusion

3. Downtime on Sunday 17th June

4. Poll results

5. Latest from the math blog

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## 1. This Month's Math Tip: ESTIMATE, SOLVE, THEN CHECK

Do you:

* Dive into your math homework and try to finish it off in the shortest possible time?

* Get some answers, close the book, then move on to do something else?

* Have no idea if your answers are correct?

[I've come across many students who do all of the above and don't even check their answers in the original question, let

alone from the back of the book...! Also, I'm amazed how many students come out of a test and have 'no idea' whether they did

OK.]

The problem with the above approach is that it is like the lottery. Sometimes you strike it lucky and get the correct answer - many times you do not. And in the end, you don't even know WHY you got some of the questions right.

One way around this problem is to use **Estimate - Solve - Check**.

This simple process is useful for math word problems - and for examinations.

**ESTIMATE** your answer first and write it down. If you know the answer should be around 10 cm, and then your final answer is 25 cm, you know something has gone wrong. But if your final answer is 9.4 cm, you can relax because it is reasonable. The ESTIMATE step really helps your understanding of the problem.

**SOLVE** the problem by setting up the equation and finding the required value. WRITE A SENTENCE for your answer. This helps you to make sure you are correctly finding what the question requires. In general, if you are solving a word problem, give the final answer in sentence form.

**CHECK** your answer against your estimate. Then, if it is close, check your answer in the equation you originally set up. Finally, check your answer in the back of the book.

For examples of the approach I am talking about, see: Applied Verbal Problems

Also, see the first question on this page: Logarithmic and Exponential Equations

For each question, I have made an estimation, I have solved the problem and then I have checked the solution. I can be sure it

is correct - I don't even need to check the back of the book š

Experience that 'warm inner glow' from KNOWING your answer is correct - and that you have learned something valuable about the

problem in the process.

## 2. APOLOGY

In the May IntMath Newsletter, a small number of readers were surprised to see their own names mixed up with the Testimonials

that I included. This was due to a strange server glitch. I apologise to you if you were affected.

## 3. DOWNTIME ON SUNDAY 17TH JUNE 2007

Due to server maintenance, Interactive Mathematics will not be available for 2 hours on Sunday 17th June.

Australia: 1500 to 1700 EST

Singapore: 1300 to 1500

India: 1030 to 1230 (Mumbai)

UK: 0500 to 0700

USA: 0300 to 0500 (New York)

Sorry for any inconvenience.

## 4. LATEST POLLS

Who are you? Why did you come to Interactive Mathematics?

See what 2,000 readers said at Intmath Polls.

The current poll asks when is the best time of the day for you to study mathematics. You'll find the poll on every page in the

site.

## 5. LATEST FROM THE MATH BLOG:

1) FRACTALS - THE COLORS OF INFINITY

Everything you wanted to know about fractals - in a movie.

2) SKILLS YOUR CHILD NEEDS TO KNOW THAT SHE'S NOT GETTING IN SCHOOL

Everyone has pet views on what should be taught in schools. This list is a good one.

3) TOWARDS MORE MEANINGFUL MATH NOTATION

One of the many confusions in mathematics is the way it is written. Here's a suggested alternative, for functions and

concepts that do not follow simple algebra rules.

4) WHAT'S IN YOUR PRIVATE MATH UNIVERSE?

Some interesting videos showing how students develop mathematics concepts.

5) INDEXED - A FUN, WACKY BLOG

Indexed is a fun, thought-provoking math-inspired blog.

Enjoy reading

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