Homeschool Math Newsletter, Vol. 11
August 29, 2007

Hello again! This is Maria Miller from HomeschoolMath.net and MathMammoth.com.

School is getting started, summer is about over, and for many of us it is time to get busier again after vacation. I've had a busy blogging month in August, so the content for this newsletter comes from my blog.

You can get educated about percent-related topics, search my blog for various math topics, and enjoy the other juicy tidbits.

In this month's newsletter:

1. Basics of percent
2. Percent of change
3. Search my blog for math topics
4. Tidbits

1. Basics of percent

The word "percent" means "per hundred", as if dividing by hundred — a hundredth part of something.

We treat some quantity (say 65 or $489 or 1.392 or anything) as "one whole". This "one whole" is then divided to hundred equal parts in our minds, and each such part is one percent of the whole.

If the "one whole" is 650 people, then 1% of it would be 6.5 people (if you have a practical application, you'd need to round such an answer to whole peoples of course).

If the "one whole" is $42, then 1% of it is $0.42. Also, 2% of it would be $0.84.

So to find 1% of something, divide by 100. To find 24% or 8% or any other percentage, you can technically first find the 1%, then take that times 24 or 8 or whatever is your percentage.

Continue reading: Basics of percent

2. Percent of change

When some quantity changes, such as a price or the amount of students, we can measure either the absolute change ("The price increased by $5" or "There were 93 less students this year"), or the percent change.

In percent change, we express WHAT PART of the original quantity the change was.

For example, if a gadget costs $44 and the price is increased by $5, we measure the percent change by first considering WHAT PART $5 is of $44. Of course the answer is easy: it is 5/44 or five forty-fourths parts.

Continue reading about percent of change here.

Another post explores in detail this question:

There are 20% more girls than boys in the senior class.
What percent of the seniors are girls?

You should try to solve it yourself first. Then read the solution and discussion here.

3. Search my blog for math topics

I upgraded the blog template to the new one that Blogger provides, and then added the searchable "labels" in the side bar.

So now you can click on any of those "labels" (down on the right side), and find my past posts on that topic. I've written nearly 300 posts since I started the blog (in late 2005). Of course not all of those posts are of mathematical topics, but there is still quite a bit of material that is still as good as ever.

For example,
Search posts labeled "elementary"
Search posts labeleled "geometry"
Search posts labeled "algebra"
Search posts labeled "word problems"
...and so on.

Hope this new feature improves the functionality of this blog.
Hop on to the blog, search the labels, and enjoy reading!

4. Tidbits

A free download of a digital Algebra 1 book offered by KineticBooks.com! Don't let this go by! It is algebra teaching software, actually.
If you're a math teacher, you might be interested in a new Master's degree in mathematics teaching and learning offered by the university of Drexel, in collaboration with the Math Forum!
Knowing how much expertise the folks at Math Forum have this might be a unique opportunity for those math teachers who want to extend their education.
Geometry fun with Geomag. While on vacation, a friend of mine gave my older daughter a set of Geomag. This has proved to be a fantastic learning toy! She's thoroughly enjoying building various shapes. Continue reading about Geomag here.
Math Doesn't Suck is a girl math book whose cover looks like a girl magazine, but inside it should be solid fractions, percents, ratios and similar middle school math topics.

It's written in a "girly" style to middle school age girls, by the actress Danica McKellar (best known as Winnie Cooper in "The Wonder Years", inspiring them with the idea that math is not far from girls' life and activities. The book includes mentions of baking cookies, fashion, makeup, and such girly topics. Read more here.