## Friday, March 14, 2014

### Pi Day

This may just be my nerdiest post yet, but I could not resist a fun little blog entry on Pi Day. If you don't celebrate this in your house, you are missing out. What is Pi Day you ask? Pi Day happens every year on March 14th (3/14). This day is the calendar equivalent to the first 3 digits in the number Pi (3.14). If you are really dedicated to the festivities, you will remember to have an extra celebration at 1:59, representative of the next 3 digits of pi. Anyway, in honor of this day, I bring you some interesting tidbits of information about Pi.

1.) Pi is the number you get when you divide the circumference (the distance around the circle) by the diameter (the distance across the middle of the circle). It is most commonly known as 3.14. It isn't known who exactly began the hunt for the digit pi, but it was likely the Egyptians or Babylonians. Can you just imagine them wanting so desperately to have a rational number to represent this ratio and instead they got pi? Well, they didn't really know it was pi yet, but still.

Here's an interesting way to remember the formula for the circumference of a circle.
Circumference = Pi * Diameter
Crust = Pi Dough

Get it? I never forgot this formula after I heard this.

2.) Here's a staggering fact. We (not me, but somebody) have calculated more than 10 trillion digits of pi. Whenever I hear that, I picture somebody sitting in a room with a long piece of paper, working out this massive long division problem. I just hope they haven't made a mistake somewhere. Fortunately, it's not human calculation that has achieved 10 trillion digits, but rather computer calculation... which I also hope hasn't made a mistake.

3.) A man named Chao Lu set the Guiness World Record for most digits of Pi memorized. He trained for 4 years, and spent just over 24 hours reciting almost 68,000 digits of pi from memory. Who does that? I wonder if how many he still remembers and if it serves him any useful purpose at all.

4.) This is an interesting website with some fun pi videos, just in case your interested.

5.) There is also a website where you can search any number (like anniversary or birthday) to see where and how often it appears in the number pi. For example, I put in my anniversary, 12071996, and learned that those exact digits occur after 12,880,005 digits and only occurs one time in the first 200 million digits. Pretty rare, huh? Go ahead and try it.

6.) What my students are doing for Pi Day: Well, I will probably share information from 1, 2, and 3 from this post, watch some videos from number 4, and play around with the website from number 5. For most of the class though, we will do a pi investigation where students measure the circumference and diameter of different circular objects on a chart. When we have a chart full of numbers, we will then divide the circumference from diameter. After throwing out the outliers, we will average the remaining numbers and see how close we come to pi. Every time I have done this, I am shocked how close we get. I will also read the book Sir Cumference and the First Round Table. It's a cute book with characters like Sir Cumference, Lady Di of Ameter, and their son Radius. It's a children's book but Middle Schoolers love it too.

7.) What our family will do for Pi Day? Well, we will probably have Chicken Pot Pi, some pineapple, and some pina coladas, and be grateful for whoever made this a day of celebration. I may even have the boys do a circle scavenger hunt.

Happy Pi Day Friday!