Homeschool Math Newsletter, Vol. 43, September 2010

New this fall: IXL now includes 7th and 8th grades!

From Pre-K counting to eighth-grade algebra, IXL has more grades, more skills, and more fun than ever. Excel in math; excel in life... Visit IXL today. Excel in math... IXL.com

Hello! It is the start of the school year for many. This time the newsletter is concentrating on geometry.

1. Math Mammoth Geometry 2, including free samples
2. Harold Jacobs Geometry: a review
3. Why is high school geometry difficult? An updated article of mine.
4. Tidbits

1. Math Mammoth Geometry 2

I have just finished writing the material for Math Mammoth Geometry 2 book. The material in it is suitable for grades 6-7. Download price is $5.80.

The main topics in the book include:

angle relationships
classifying triangles and quadrilaterals
angle sum of triangles and quadrilaterals
congruent transformations, including some in the coordinate grid
similar figures, including using ratios and proportions
review of the area of all common polygons
circumference of a circle (Pi)
area of a circle
conversions between units of area (both metric and customary)
volume and surface area of common solids
conversions between units of volume (both metric and customary)
some common compass-and-ruler constructions.

I've included several complete lessons from the book as samples (PDF). Feel free to download these and use with your students!

Angles in Polygons
Review: Area of Polygons, 1
Surface Area

Besides those, there are two other sample pages:

Area and Perimeter Problems
Basic Compass and Ruler Constructions, 1

What is next?

2. Harold Jacobs Geometry: a review

Harold Jacobs Geometry: Seeing, Doing, Understanding (third edition) is an Euclidean geometry textbook meant for a high school geometry course (typically grade 10).

I had been wanting to get a copy of this book for years, and I kept looking if I could find a used copy for $10-$20 somewhere. But after several years, I decide that just wasn't going to happen, and got me a used copy for what they generally sell: between $30-$50. That price alone tells you about the popularity of this book.

Of course Jacobs' Geometry isn't popular without a reason. I will strive to explain here why people like it so well.
First of all, it has to do with Jacobs' writing style: he clearly loves geometry (and mathematics) himself, and writes about it in an interesting and humorous way. Every new lesson starts out with some clever notion of that particular geometric topic taken from real life, often from cartoons. So... it is not written as a "facts book" alone, but as a book that you enjoy reading through, even if you weren't studying geometry.

And secondly, the exercises. It is here that Jacobs really exceeds. A tremendous portion of the exercises are tied in with real-life examples and illustrations, which makes them more interesting than regular textbook exercises. They often cite old math books or math books from other cultures, or come from art, architecture, nature, illusions, sports, chemistry, geography, astronomy, etc.

Continue reading my review of Harold Jacobs Geometry

3. Why is high school geometry difficult? An updated article of mine.

This article is in two parts, and may be of interest to even when your student is in middle school.

Part 1: High school geometry: why is it so difficult?
and
Part 2: What can be done to make high school geometry less of a pain?

4. Tidbits

The problem with the equal sign (misconception)
According to the research, US students exhibit this misconception much more often than students in other countries. It has to do with thinking of the = sign as an operator. Kind of like thinking that = means "to do" the operation.
Cathy Duffy's review of Math Mammoth
Cathy Duffy is a well-known curriculum specialist who reviews all kinds of homeschooling resources.
Math assessment and placement
Check out these resources for math assessment and placement, and how my daughter did with her 4th grade end-of-year test.
Math tricks by a silly guy
A short youtube video where Kjartan Poskitt shows some math tricks. He's funny! Enjoy!
Factoring the Time
Just a funny comic strip about factoring.

Till next time,
Maria Miller

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