# April 2011 Archives

## Samples and Surveys

It's fairly impossible to survey the entire population for their opinions or preferences. Because of this, most people use what is a called a sample, a part of the population being surveyed. They then use the results from the sample to conclude what the population would think, a population being the entire group being considered for a survey.

There are several sampling methods including random, systematic, stratified, convenience, and voluntary response. In today's free 8th Grade Math video, Prof. Burger covers these sampling methods. He also demonstrates how some sampling methods are better than others and how to identify bias in a sampling method.

Look in any newspaper and you'll see how often surveys are utilized to determine population trends. This is great information that will come in handy as you read statistics and news articles discussing results of polls and surveys. You'll not only have a better understanding of how they reached their conclusions, but whether or not to take them seriously due to a sampling error or bias. Just make sure you click the forward button to the left of the time stamp to move to the next lecture on the video. Today's video has 3 lectures that clearly explain the concept of Samples and Surveys.

## Displaying Data

There are many, many ways to display data including bar graphs, histograms, pie charts, and line graphs. The key is finding the most effective way to present your data and create the impact you want. In today's free 8th Grade Math video on Displaying Data, Professor Burger starts things off by demonstrating a frequency table. A frequency table is a table that lists the number of times, or frequency, that each data value occurs. He takes the data from the frequency table and creates a double-bar graph, which is a bar graph used to display and compare two sets of data. What becomes readily apparent is how important the visualization of data can be in showing trends and making a list of numbers have meaning.

But wait, there's more! This is only the first lecture! Clicking the forward button to the left of the time stamp will get you two more lectures discussing histograms and line graphs. By the end of today's lectures, you will be ready to attack the included topic worksheet. Check out the video, complete the work sheet and understand the beauty of displaying data.

## Scale Drawings and Scale Models

We encounter scale drawings almost everyday. Maps are a good example of scale drawings as they are two-dimensional drawings that use a scale to represent an object as smaller or larger than the actual object. Most of us encounter scale drawings in a variety of places, whether it is on our phones trying to figure out how to get someplace new, or a diagram in a science book of the minuscule parts of a cell. It's important to understand how to properly utilize a scale to determine the actual size of an object or the distance between two points. While an inch might not seem very far, if the scale is 10 miles = 1 inch, you might think differently.

The same goes for scale models. Sometimes it's just not possible to create a life-size model of something, whether it is a volcano or something tiny like the nucleus of a cell. This is where making a model to scale becomes useful. Professor Burger shows you how to use ratios to find unknown scales and find unknown dimensions based on a scale. He even demonstrates real world applications of these concepts in today's free 8th Grade Math video on Scale Drawings and Scale Models. Don't forget to click the forward button directly to the left of the time stamp to move to the next lecture on the video. There are a total of 4 lectures today and you won't want to miss a second!

## Why Our Kids Are Falling Behind in STEM Education

We all know our education system is currently in an uproar. Schools are dealing with serious funding cuts, and in response, teachers are being laid off at an unprecedented rate. Schools are also cutting back on field trips and hands-on activities that they consider costly extras, despite the fact that our students are lacking in the areas of math, science, and technology--the very fields where field trips and hands-on activities could help. The fact that American kids are quickly falling behind the rest of the world in science and technology is a sad fact, considering what an interesting and interactive subject it is.

It is most unfortunate that science fairs and interactive science activities are fading from schools. This year, due to local sponsors dropping out, several of the largest science fairs in the country were under threat of cancellation before corporate sponsors saved the day. Yet these events are exactly what can engage a student and spark an interest in learning more about how the world around us works. I've seen several experimental programs that target exactly what kids need to bring them back to science and help our country stay on top in the future of scientific development. The problem is going to be how schools can afford such programs when they are cutting their budgets to the bone.

I recently attended a local conference called Let's Play, A Corporate Citizenship Conference. I had the opportunity to listen to a panel discuss partnerships in education. The speakers, all currently working in the world of education, were talking about current issues in education, with funding being the focus. Susan Dawson from the E3 Alliance was one of the panelists and she brought up the disconnect between STEM (Science, Technology, Engineering, and Math) education and the careers related to the subjects. An audience member brought up the fact that the most in-demand jobs are basic programming jobs that tend to pay very well. Anyone can learn how to program, yet it's rare to find programming classes in high school. How did this audience member know that? She happened to be a programmer for a living. Here is one of the biggest elements missing from a majority of school classrooms: people talking about their careers and what it took to get the job. We all know what acting, writing, and other high-visibility jobs entail. However, most students couldn't tell you what a Ruby on Rails programmer or an endocrinologist does.

I would bet most students would write off biotechnology research as "uninteresting," despite the fact that many students are concerned about the environment, where biotechnology is particularly relevant. This is a perfect example of an area in which a school could make a big difference by having a person in the field come speak to students--or, as one school did, provide students firsthand experience in the scientific process and link it to current social issues. Many kids are concerned about the environment, and exploring a clean fuel alternative, as the class mentioned in the link above, is a great way to connect that passion to a potential career.

When I was young, my favorite class was science because of all the experiments and hands-on activities we did. Even in college, I enjoyed the science lab much more than the class that required it. Actively participating in something and experiencing the results is much more interesting and sticks with you better than a lecture about an experiment. Whether it's in the classroom, at home, or even at a science museum with interactive exhibits, getting to experience science hands-on usually has more impact than a textbook.

Many of you may be wondering how this translates into a homeschool or online curriculum. I've seen many science lab kits for sale that are a great way to get the kids involved at home. A nice microscope can go far by allowing kids to look at anything they encounter in the world, and there are oodles of kitchen experiments you can do with your kids. While you won't be actively participating in labs with the Thinkwell curriculum, we recognize the importance of demonstrations and make a point to include them in our science courses. Some of my favorite lectures are the Chemistry in Action demos with Professor Gordon Yee, especially because these are often experiments you wouldn't want kids to be involved in, but the results can make a big impact.

STEM education has become the big buzzword in education right now. Even the president is focusing on it, recognizing the importance of STEM to our country's future success. Hopefully, the folks deciding where the money goes will also see the importance of helping students get their hands dirty in science and computer labs, and will invest where the money can really help.

## Creating the Periodic Table

The periodic table is often the first thing that comes to mind for many people when thinking about chemistry. Many of us have seen it as early as grade school and it's a great reference for learning more about the different elements. Did you know that only 15 elements were known in the 1700s? As the number increased, many people attempted to find a way to organize them. Today's free Chemistry video is about the history of the periodic table and how it evolved into the useful tool it hanging in all chemistry classes.

It wasn't until Dmitri Mendeleev took a stab at it that what we know as the Periodic table began to evolve.  He saw that it would be possible to arrange the elements in order of atomic weight and chemical reactivity. Based upon his new organization, Mendeleev noticed some missing spaces and using the chart was able to make predictions about undiscovered elements that turned out to be very close to reality. As scientists began discovering more elements, they encountered new issues that instigated further changes to the order of the table. These discoveries caused scientists to realize that atomic number, or the number of protons in an atom, is a better criterion than atomic weight in ordering the elements. It was this realization that resulted in the table we know today.

## Celebrate Earth Day!

Did you know that for over 40 years, Earth Day has inspired awareness and appreciation for the Earth's natural environment? United States Senator Gaylord Nelson founded it in 1970. Initially focused on just the United States, it became an internationally recognized day in 1990.

What I like about Earth Day is coming up with fun activities that bring home different ways to recycle and enjoy the world around us! Learning to love our home planet and take care of it is important, so here's a great list of resources to help you celebrate Earth Day.

Earth Day Wikipedia page - I was surprised by how much history was behind this day. It's interesting to read how it came about and how other countries celebrate Earth Day.

Earth Day Network - This is the organization that coordinates Earth Day celebrations across the globe. Site has lots of great information and suggestions for activities.

A Billion Acts of Green
- Earth Day Network has set up a page where you can choose from a list of  "acts of green" and pledge to participate in them. Everything from turning lights off when you leave a room to writing a senator are suggested here.

Our government maintains an Earth Day Page - through the Environmental Protection Agency. You can read about environmental issues, green science and technology and ways you can take action to help our environment.

Keep America Beautiful - is a great resource for litter prevention, waste reduction and recycling.  Picking up trash is a great activity as it helps kids see that just one piece of trash tossed can quickly add up to a real mess in the long run! They even have a kids' section with games and a couple of brochures with information on how kids can help keep America beautiful.

The Nature Conservancy - is celebrating Earth Day with Picnic for the Planet. Meet up with other folks in your city to celebrate Earth Day outside. They have recipes for picnic inspiration and tons of already planned meet-ups for this celebration.

We'd love to hear what you have planned for Earth Day? Will you be picking up litter in your favorite park or maybe taking the kids to a recycling plant to learn how it all works? Share with us in the comments section!

## The Fate of Absorbed Nutrients

We've been talking about digestion this week and yesterday's video focused on how nutrients get absorbed into our blood and then our lymph system. But where do nutrients go from there? Well, it depends on our body's metabolic state, of which there are two. There is the absorptive state, which is the period during and just after eating in which the digestive tract is full, nutrients are entering the circulatory system, and anabolic processes exceed catabolic processes.  The other metabolic state is the post-absorptive state where the digestive tract is empty and the body is using stored reserves of energy to maintain metabolism. Yes, I know there are some big vocabulary terms in these two statements, but fear not! Just watch today's free Biology lecture on The Fate of Absorbed Nutrients to learn about how our body absorbs nutrients during both metabolic states.

## Human Nutrition: Absorption

Yesterday I posted an overview of the digestive system. If you watched the lecture, you learned about the organs involved in digestion and the 3 major roles of digestion: ingestion, digestion, and absorption. It's always great to gain a better understanding of how our bodies work and absorption of nutrients really connects the dots from food to fuel. That's why today we are jumping into Human Nutrition: Absorption.

In today's free Biology video, you'll learn more about how our food is completely digested by enzymes and then passed into your blood. Nutrients must get from the small intestine and into our blood so that they can move around the body. While we know the small intestine is a very long organ, the surface area of its lining is even more than you would ever imagine thanks to villi. Villi are finger-like projections that line the small intestine, increasing the surface area and thereby maximizing the uptake in nutrients. They do much more than that, but you'll need to watch the video to find out more.

## Introduction to the Digestive System

I thought this would be a perfect video to post for lunchtime: Introduction to the Digestive System. Learn exactly what happens after you take a bite of your lunch and what processes it goes through as it is digested with today's free Biology lecture. Did you know that we have specific teeth adapted for our omnivore diet? You'll learn more about that and the major roles of digestion: ingestion, digestion and absorption. Professor George Wolfe starts at the beginning of digestion in the mouth and goes through the entire digestive system to the end: the large intestines. This is a great overview of the digestive process and you'll see how fascinating our bodies are in breaking down the food we eat for fuel. I love Prof. Wolfe's sense of humor and it definitely comes through in today's lecture.

## Worksheet - Radical Expressions and Rational Exponents

Hope you enjoyed the lectures yesterday! With Radical Expressions and Rational Exponents being a challenging math topic, I figured it would be perfect to post the accompanying worksheet for this lesson. Printable worksheets are one of the best things about our online curriculum. We do have required exercises after each video, but students often need a little more practice to firmly understand a concept. That's why these worksheets are a great way to reinforce what has just been learned.

Today's Algebra 2 worksheet is two pages of questions covering yesterday's video. Print it out, test out your knowledge and see how much Prof. Edward Burger taught you.

## Radical Expressions and Rational Exponents

I've been reading in several sources about public schools requiring Algebra II in high school. This is apparently because Algebra II is a good indicator of college and work success as noted in this Washington Post article. Looking over the sample problems they display with the article makes Algebra II look scary and full of rational exponents. But there need not be any fear as long as a good teacher is on hand to explain these concepts. And we've got the perfect solution with our Algebra II course taught by Professor Edward Burger!

I could think of no better set of lectures to highlight than the 6 covering Radical Expressions and Rational Exponents. This topic covers everything from finding real roots and simplifying radical expressions to writing expressions in radical form and simplifying expressions with rational exponents. Whew! Each subject is a natural progression into the next one, which is why I think everyone can benefit from today's video! Just remember that there are a total of 6 lectures on today's video and you'll need to click on the forward button to the left of the time stamp to move to the next one. Definitely view them all, the last one has a practical music application for all these concepts!

## Favorite Homeschool Supplies

What is the one homeshool supply you can't live without? It's a simple question and yet when I posed it to homeschoolers online, I was surprised by the answers. I, of course, made certain that kids weren't an answer, as we all would give that one. But it came down to three main responses. One answer was BBC documentaries, something I have heard many homeschool parents mention. Seems that they produce high quality documentaries that are great for students. The number one answer was a computer. Completely unsurprising in this day and age and definitely one I appreciate seeing as it is an amazing resource. The second highest response was an inquiring mind. I wouldn't have thought of this as a supply, yet it rings true as a very important aspect of homeschooling. One of the beauties of homeschooling is the freedom and lack of rules. Yes, many states require you to submit samples of work or have your child take a test to prove they are learning. But without an inquiring mind, homeschooling doesn't work as well. I love the beauty of a parent letting their child's interests lead their education and how often it is the best way to develop a life-long love of learning. I think students who don't want to learn are not the best homeschool students. Isn't that why we homeschool, after all, to teach children to enjoy learning?

I was impressed with the answers to this question. Still hoping to get more. If you have a chance visit us on Facebook and add your two cents or just post below. I love hearing about people's homeschools and what works for them!

## The American Two-Party System

Things have definitely been changing in the political arena lately. However, as much as things change they also tend to stay the same, and two political parties have always dominated our country's elections. This is not to say there aren't other political parties out there. But, when it comes down to it, America has two main political parties: Republican and Democrat. While the past election saw some changes, if you look at Congress you'll see it's still primarily composed of members from the two main parties. Why is this the case and why do so many of the smaller parties have a difficult time getting elected? Watch today's free AP American Government video on The American Two-Party System to find out why. Professor Mark Rom shows how often the structure of our election system maintains a two-party system. Of course, as with most things in politics, it is much more complicated than that and today's lecture strives to touch on many of the reasons for why other parties have a more difficult time capturing elections.