Cell size and scale

Just a neat link my hubby found this morning...

http://learn.genetics.utah.edu/content/begin/cells/scale/

You can zoom in to see these various things starting from a coffee bean and down to a skin cell, human egg, red blood cell, bacteria, viruses, hemoglobin, glucose and molecules, etc., all the way "down" to a carbon atom.

In measuring scale, you go from millimeters (0.001 or 10^-3m) to micrometers (0.000001 or 10^-6m) to nanometers (0.000000001 or 10^-9m) to picometers (0.000000000001 or 10^-12m).

American Math Challenge

The American Math Challenge is an online math challenge or "competition" where students aged 9-14 from across America can compete in a safe, multiplayer game environment.

This is from the same folks as the World Math Day, if you happen to remember that.

Students will have the task of answering as many correct questions as they can in 60 second mental arithmetic challenges LIVE, against other students. Or, they can also solve questions based on the national curriculum at their own pace.

Why would you take part?

• It's about having fun with math. In fact, there's a good chance your students/children will love it.
  
  
• It's absolutely free. Nothing to lose if you participate. In fact, during the practice week you can find out if your kids like it or not.
  
  
• If your children or students really get into it, they can vastly improve their mental arithmetic and basic facts.
  

Week 1: Nov. 2-8 is Practice week
Week 2: Nov. 9-16 is the actual American Math Challenge

Register at www.americanmathchallenge.com

Wolfram|Alpha homework day

Today October 21st is a Wolfram|Alpha Homework Day. I am not quite sure myself what all this entails, but it is a LIVE interactive event on the web, revolving around what can be done with Wolfram|Alpha search engine.

Here are some highlights (from the website) of what will be happening over there today:

• A special Homework Day Welcome from Stephen Wolfram
• A demonstration by a forward-looking elementary school teacher of lesson plans that use Wolfram|Alpha
• A conversation with the creator of "Shift Happens" about tech trends and their impact on education
• A fun experiment with Wolfram|Alpha's mad scientist Theodore Gray
• Several live, interactive Q&A sessions where Wolfram|Alpha scholars and experts help you tackle your homework questions
• A special live Q&A session tackling the toughest math questions

• A thought-provoking in-depth conversation with an internationally known actor and education advocate
• A live interview with the creator of the Ning social networking group Classroom 2.0
• An insightful dialog with an award-winning physics professor and best-selling author of several popular science books
• A vibrant panel discussion of teaching with technology led by noted journalist Elizabeth Corcoran
• Several live, interactive Q&A sessions where Wolfram|Alpha scholars and experts help you tackle your homework questions
• A special live Q&A session tackling the toughest math questions

• An interview with a renowned theoretical physicist, best-selling author, and frequent PBS contributor
• A special live Q&A session tackling the toughest science questions
• A live concert by Common Loon
• A demonstration of Wolfram|Alpha examples from an innovative college professor
• Several live, interactive Q&A sessions where Wolfram|Alpha scholars and experts help you tackle your homework questions
• A recap of the best highlights of Wolfram|Alpha Homework Day

http://homeworkday.wolframalpha.com/

Math Teachers At Play carnival #17

Math Teachers At Play #17 carnival is posted at Math Recreation. LOTS of stuff there this time!

Here are some of my picks: Circle of fifths and roots of two is of interest if you have studied music. This post explains the difference between equal temperament and Pythagorean tuning, from a mathematical point of view. All about A4 explores this common paper size and its special properties. And Pat's post You Might Be a Mathematician IF... was quite funny.

NAEP math test results are in

The National Assessment of Educational Progress (NAEP) math tests given early in 2009 show that the US fourth graders scored the same as in 2007, and 8th graders gained a little over 2007 tests. This is commonly called "the nation's report card".

I guess it shows things haven't changed since 2007 in the realm of math education; however the test results are better now than when they first started administering the test in 1990's.

If you are interested, NAEP Mathematics 2009 website has charts and much more information.

10/10 and the Metric Week

Photo courtesy of Miss Colleen

Today is 10th of October or 10/10. As we know, the metric system is based on number 10. Thus, the week ending today has been designated as the metric week..

The National Council of Teachers of Mathematics (NCTM) started the National Metric Week tradition in 1976. Please read a little bit more about the history of the Metric Week here.

You could celebrate the Metric Week doing some metric units puzzles and quizzes. Here's a link to postal stamps and cards celebrating the metric system.

NCTM has tons of related resources so I'll mainly point you there.

I grew up using the metric system, and so I've actually had to learn the imperial system while authoring math materials. These days, it seems, I know the U.S. system better than the people around me... But the metric is sure easier, as far as calculations and conversions go, since you just have to remember it goes by 10s.

In fact, to fully operate in this world, it seems it's best to know both.

Converting between metric and U.S. measuring systems

Here are a few helpful guidelines if you find yourself having to switch between one or the other. I have these conversion factors memorized from much of use. Not that everyone else would actually use these all as much as I do, being in the business of authoring math materials, but anyway:

1 quart ≈ 1 liter, but 1 quart is slightly less.
1 liquid ounce ≈ 30 ml. From this, one can figure out that 1 cup ≈ 240 ml and 4 C ≈ 960 ml.

1 inch = 2.54 cm
It's an awkward number but I need to use this conversion factor constantly, when working with images on my computer, which has a resolution of 96 pixels per inch... but I need the image to print out as 5 cm long or whatever.
You could use 1 inch ≈ 2.5 cm.

Another way is to think about those typical student rulers which are 12 inches = 30 cm. So... 4 inches is 10 cm.

Also... 1 inch might very well be the length of your thumb's last bone (the bone that contains the nail). Check! And 1 cm might very well be the width of any of the other fingernails. Check!

1 yard ≈ 1 meter; better yet 1 yard ≈ 90 cm and 1 meter = 100 cm. You see, that student ruler was 12 inches = 1 foot ≈ 30 cm.

1 mile ≈ 1.6 km. Or, 5,000 meters or 5 K is a popular running distance... about 3 miles.

1 pound is about 450 g, but actually it's easier to remember 1 kg = 2.2 lb.

It's fairly easy to multiply by 2.2. I have a metric scale; I might weigh about 55 kg. 55 x 2 = 110 and 55 x 0.2 = 11. So I weigh about 121 lb.

And 1 ounce ≈ 30 g. Just like 1 liquid ounce was about 30 ml.

To convert anything, go to Google and type

25 lb to kg
8 m to inches
22 km to miles
etc.

Math contest for homeschoolers (elementary)

Noetic Learning is holding a math contest for elementary students that homeschoolers can take part in. Here are some details about this contest:

• Registration deadline: October 18,2009 (coming up soon!)
  
• Contest Date: October 26-30 2009
• Who: any students (grades 2 - 5)
• Location: your home
  
• Fee: $8 per student per contest

My daughter is taking part. We will see how it goes. The purpose of a math contest is definitely NOT to discourage a child or to put additional burden on him. I'm basically checking to see if this contest can be a means of inspiration and motivation for my daughter.

www.noetic-learning.com/mathcontest/homeschool.jsp

Spread of H1N1 (swine) flu and mathematics

I came across an interesting blog post by Murray Borne titled H1N1 and the Logistic Equation. It explains how a logistic function can be used to model the spread of a virus or a disease in a given population.

Now, maybe you don't know what is logistic function or equation. It is shown in the blogpost; it uses the exponential function as a part of it. Basically, it is like an exponential growth function but it is limited after a certain point so that the growth tapers off, and approaches a certain (upper) limit.

Murray shows the graph, and then shows a real-life example about the spread of swine flu in Mexico last spring. It's a great, yet fairly simple, example of how mathematics is used for modeling real-life situations.

You could definitely use it as such an example with your students, even if you don't understand a THING about logistic equations. You see, seeing how math is used is definitely inspiring and motivating to a lot of students - especially when it ties in with some current "hot topic" such as the H1N1 flu.