## Saturday, March 24, 2012

### Podcast Blog # 2

Podcast: Math Dude

Episode: How To Raise an Exponent to a Power

As I continued following the math dude podcast, I listened to the next episode called “How to Raise an Exponent to a power”. In this episode, math dude explains the importance of exponents. He tells his listeners that the further in math you go, the more important they become. First, he quickly reviews how to multiply exponents. After that he gets into telling listening what is means to raise an exponent to a power. He explains that an exponent is the little superscript number that tells you how many copies of the base number to multiply together. So, in the case of (2^3)^2, the exponent 2 tells us that (2^3)^2 is the same thing as 2^3 x 2^3. In the same way, we can now unwrap each of these 2^3s using the fact that 2^3 = 2 x 2 x 2 to find that the problem (2^3)^2 = 2^3 x 2^3 = 2 x 2 x 2 x 2 x 2 x 2. In other words, it’s equal to 2 multiplied by itself 6 times—that is, 2^6. After he explains this, he gives a quick and dirty tip.   The quick and dirty tip for raising an exponent to a power is to simply multiply the two exponents. So instead of uncoiling the whole problem like we did before and multiplying everything out, we can simply multiply the exponents—3x2=6—to find that (2^3)^2 = 2^(3 x 2) = 2^6. At the end of this episode math dude gives several practice problems.

Episode: How to Write Small Numbers with Scientific Notation

The next episode I watched was called “How to Write Small Numbers with Scientific Notation”. In this episode he begins by reviewing what Scientific Notation is. He then explains what “really tiny numbers” are. He says “When I say small number I’m talking about a number with a small absolute value—that is, a number that’s much smaller in magnitude than the number 1. For example, in this sense the diameter of a hydrogen atom—which is about 0.000000005 cm—is a really small number.” The next things Math Dude explains is what negative powers of 10 are. A negative exponent tells you how many copies of the base you need to divide by. So 10^–2 means to divide 1 by 10x10. In other words, 10^–2 is equal to the number 1/100 = 0.01. Lastly, he explains how to use scientific notation to write small numbers. Remember that writing very small numbers using scientific notation is just like writing very big numbers except the exponents are negative. Before concluding the episode, math dude give several practice problems.

Episode: What is Pi?

The last episode I watched was called “What is Pi?” First, math dude begins by explaining what the meaning of Pi is. The origin of the number that we call “pi” for short (and usually write with the Greek letter π) that’s equal to approximately 3.14 has a very easy-to-understand meaning. He explains how to make a perfect circle, then tells his listeners how to use that circle to find Pi. The next thing he does is tell everyone what Pi is. The ratio of the circumference of a circle to its diameter is always pi…no matter what circle you draw. Lastly, Math dude sums up by explaining what Pi day is. Pi is 3.14 and if you turn this number into a date, you get March 14. This is why every March 14 math enthusiasts around the world gather together across the interwebs to celebrate and enjoy some pi. And the good news is that everybody is invited to celebrate in whatever way moves them.

Official Pi Day Website
Activities for Teaching Pi

Podcast: Grammar Girl

Episode: Bring Versus Take