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Showing posts from December, 2008

### What's in the name "Math Mammoth"?

Well, folks, you might be in for a surprise, but when I was thinking what to name my math program.... You know, first of all, English isn't my native language. Secondly, I'm not super creative when it comes to naming math programs. I chose "mammoth" because it sort of rhymes with "math". I thought people would be able to REMEMBER it easily! You know, let's say a person stumbles on my website, and days later they try to remember what was it called? Maybe, just maybe, the woolly animal would have made a connection, even if an amusing one, in their mind. So there you have it. There are no hidden implications. It's not ancient math, nor "humongous" in any sense. The math in "Math Mammoth" is pretty normal and logical. All this was spurred by a really enjoyable and fun review of my books by Mary Grace at Books and Bairns. She really has a knack for writing!

### Solving direct and inverse variations in chart form

Dave Marain recently featured my blog on his, and now it just so happens I get to promote his, because I really liked his post about learning direct and inverse variations . He uses a beagle problem with interesting numbers: "Three beagles can dig 4 holes in five days. How many days will it take 6 beagles to dig 8 holes?" The solution is actually quite easy — just think how there are exactly twice as many beagles and also twice as many holes. Dave shows a chart that can help youngsters grasp the solution. I want to go one step further with this. Let's try a little more awkward numbers: "Three beagles can dig 7 holes in eight days. How many days will it take 5 beagles to dig 9 holes?" I want to show you how a "chart" approach will still work. This situation describes joint variation , because there is both inverse and direct variation involved: the number of days it takes to dig the holes varies inversely with the number of beagles (the more beagles,

### Use that brain

You know the old saying, "Use it or lose it." It definitely applies to our brain, as well, and not just our muscles (it's been proven). Using the brain can even help prevent dementia in seniors! So, if you feel that your brain isn't getting the exercise it needs amidst all the routine housework, kids schoolwork, holiday preparations, and just life, bookmark the following link list. Then, every day go to one of the sites on the list, and do one puzzle, riddle, or whatever it might be. There are plenty of sites on the list to keep you busy for a while. It says "50 games" but some of the links go to sites full of games: 50 Fun, Free Web Games to Make Your Brain Smarter, Faster, Sharper For example, promise yourself to have some brain gym time just before or after you finish reading your favorite blogs or news sites or check email in the morning. It should work!

### TIMSS 2007 results are in

TIMSS - or Trends in International Mathematics and Science Study - is an international mathematics and science assessment that is conducted every four years. The results for 2007 are in now. Happily, the United States has improved! The average math scores for both fourth-graders and eighth-graders have risen since 1995, the first year the test was administered. Most of those gains took place among the lowest-performing students. That could be a result, analysts say, of the increased focus on bringing up America's struggling students without as much attention to those at the top. (See US students improve in math .) I was trying to find a chart that would list the average student achievement by countries, but I couldn't find it directly online; only in the downloadable documents. So I took screenshots from the full report to post the charts here, for your convenience. Note: Not all countries of the world participate in the TIMSS. 4th Grade Student Achievement: 8th Grade Student A

### Origami

Origami is the ancient art of paper folding. Yesterday I was asked by my daughter to make a paper boat (after reading a Curious George book where he made them). Well, that was easy for me because I learned that when I was a child. Then she asked me to make a paper bird that she saw in the Adventures of Penrose book. I've never even attempted to make one before. The book had "instructions" but those images just looked quite cryptic. So I turned to the Internet. I found several sites that had picture instructions, but they all made me just puzzled; there would always be one step that I couldn't see how they did it. Then, I found this site: www.origami.org.uk . They had ANIMATED instructions on how to fold a flapping bird! Finally I was able to make one! Just thought I'd pass this one, in case some of you are interested in the paper folding stuff. It can be pretty fun for the kids.

### Word problem

A word problem: Luisa has four times as much money as Mary. If Luisa has \$240 more than Mary, how much money do they have in all? Mary has less. Let Mary's money be represented by ONE BLOCK. Then, Luisa's money would be FOUR BLOCKS. Now, the problem says the DIFFERENCE in their monies is \$240. The difference is also three blocks. So, three blocks is \$240. Then one block is \$80. The question was, how much money do they have in all? They have 5 x \$80 = \$400 together. The same can be solved with algebra. Instead of blocks, we use x. Mary has x, Luisa has 4x. The difference 4x − x is \$240. As an equation: 4x − x = \$240 3x = \$240 x = \$80 Then, together they have 4x + x = 5x, which is 5 x \$80 = \$400. You can use the exact same kind of reasoning and block model to solve any similar word problem where one thing is so many times as another, and the actual difference is also given. Try this on your own: A daddy elephant weighs 7,000 pounds more than his child. Also, he weighs three times

### Thanksgiving contest winners - 2

It's time to publish the winners for category 1 of Math Mammoth Thanksgiving contest. I got a lot of very nice testimonials, and in fact I'm still going through them. Some of the stories of how people have used Math Mammoth were actually quite touching. In one case, it seems Math Mammoth saved the entire homeschool (see the first winning entry below)! In others, my books have made a big difference. So without further ta-doo let's announce some winners! 1st Prize : \$50 credit to get Math Mammoth books There are two winners. 1. Coleen Posey Excerpt from her entry: "I do not exaggerate when I tell you that we were on the verge of giving up on homeschooling and putting our kiddo in school because math was ruining our entire day. That was not what I wanted to do, so back into "research mode" I went. Enter Math Mammoth. I don't even remember how I stumbled onto the website, but I soon realized it looked like exactly what we needed. What attracted me the most