Archive for the 'Math' Category
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One Last Post about Pi
Saturday, March 17th, 2007Check out Jeremy, from my previous pi post, lip-sync-singing pi to the xth digit! (Did you get what I was trying to say there? It’ll all become clear when you watch the clip…)
I thought that was too funny to pass up! –Lisa
Check out the site Super Simple Songs to see some kids videos with Jeremy in them.
How Many Numbers Can You Recite of Pi?
Friday, March 16th, 2007I’m not ashamed to admit it, here’s what I can remember:
3.14… to infinity!
Well the other day, when I wrote about Pi Day, Devon over at Head, Shoulders, Knees and all that, commented about a video we could watch of one of his colleagues reciting all the numbers listed below in pi. (He made one error in the middle – but he corrected himself. I’m jealous!)
3.141592653589793238462643383279502884197169399375
10582097494459230781640628620899862803482534211706
79821480865132823066470938446095505822317253594081
28481117450284102701938521105559644622948954930381
96442881097566593344612847564823378678316527120190
91456485669234603486104543266482133936072602491412
7372458700660631You’ve gotta watch this video of Jeremy-sensei performing this mind boggling task. It’s great!
Eat a Piece of Pie for Pi Day
Monday, March 12th, 2007Pi (π) Day is celebrated on March 14th in the US. It’s mainly celebrated by students, teachers and professors, lovers of math, and mathematicians.
In case you forgot… What is Pi Again?
Pi (π) is the ratio of a circle’s circumference to its diameter. To break it down into a simple formula:
π = circumference of a circle/its diameter
The circumference is the distance around the circle. The diameter is the distance from one side of the circle to the other, if you drew a line that passes through the center of the circle.
Pi is particularly useful when you’re trying to work out the area of a circle or an arc.
One important thing about pi is that it’s always the same no matter how big or how little the circle is. This makes sense – because a circle is always a circle – no matter how big or small it is – the ratio of its circumference to its diameter is always the same – it’s pi!
Pi = 3.14159265358979323846264338327950288419…
The … means that the number goes on an infinite amount.
The amazing thing about pi is that it’s an irrational number. Yet it’s still useful in our day to day life. Like if we wanted to figure out the area of a circular rug, you’d need to use pi. Go figure!
Why is Pi Celebrated on this Day?
March 14th is Pi Day in the US. That’s because in the US, you write March 14th as 3/14. So if you figure…
Pi = 3.141592653589793238462643383279502…
The 3.14 is where you get the 3/14 for March 14th. (To make this date even more propitious, Albert Einstein was born on March 14th in 1879.)
Of course, you’re talking about mathematicians, so figuring out what time to celebrate Pi Day isn’t simple.
Most people would say the correct time to celebrate it is at 1:59, since those are the numbers in pi that come after 3.14. There’s a debate about whether it should be am or pm. I assume college students would chose to celebrate Pi Day at 1:59 am for its accuracy (plus they can stay up to have a party in the middle of the night). Presumably most high school and middle school kids would be more likely to celebrate Pi Day at 1:59 pm. Though I must warn you that some people celebrate it at 3:14!
In Europe and other parts of the world, Pi Day is celebrated on January 3 at 4:15. That’s because they would write the date putting the number for the day first (3) and then the number for the month (1). So they’d write the date as 3/1 then add the time 4:15 and you get some of the numbers in pi: 3.1415…
Why is Pi Called Pi?
π is the Greek letter for P. π is also the first letter of the Greek word for periphery (or circumference).
How Can You Celebrate Pi?
Here are some ideas:
-Eat pizza pie on pi day.
-Make a pie with a pi sign on it to eat.
-Have a contest to see who can remember the most digits in the number pi. Perhaps the winner can win a pineapple.
-Have a pie throwing contest!
-Sing Pi Day Carols.
-Prove that π = 3.14…Idea for Teaching Pi or How to Show that π = 3.14159…
I think this is a wonderful hands-on experiment to help children understand why π = 3.1415… The gist of this experiment is to take different sized jar caps and have the children measure them. 1st they will cut a piece of string to get a measurement for the circumference. Then they will cut another piece of string to get a measurement for the diameter. Then they measure each string. Then they work out how many “diameter” strings they will need to get a measurement for the length of the “circumference” string. The answer should be in decimals. The class should take all of its data and average it out. The answer should be close to pi.
For full instructions of this experiment go to What is Pi? A “Cool” Lesson
There’s also a cool one-page pi poster you can print out for your child or students.
Many thanks to Calvin for pointing out this holiday to me!
Happy Pi Day to You All!
Lisa
100 Day Celebration
Monday, February 12th, 2007Last week I joined my daughter’s kindergarten class for their 100th Day of School Celebration.
The teacher uses the 100 Day Celebration as an opportunity to teach the class about the concept of 100. Before the big day, the children learn to count to 100 by ones, fives and tens.
The week before the celebration, each child makes a project at home out of 100 items. They’re told to include the number 100 somewhere in their project. My daughter made the number 100 out of 100 Legos. When my son was in kindergarten, he glued 100 pennies onto a board with an equal sign and a dollar, meaning 100 pennies equals one dollar.
When my son was in kindergarten, on the morning of the 100th day of school, the principal counted the children as they entered the school. The 100th child to enter received a prize.
For my daughter’s celebration, the teacher made placemats with the numbers 10, 20, 30, 40, 50, 60, 70, 80, 90, & 100 on it. The kids counted 10 each of a different snack on each number. That is, ten pretzels were placed on ‘10′, ten M&M’s were placed on ‘20′, ten little marshmallows were placed on ‘30′, etc. At the end, each child had counted 100 snacks.
Here’s what the mat looked like…
Feel free to share any 100 day activities you know about in the comments below!
-Lisa
UPDATE: You can see a photo of my daughter’s 100 Day Project plus more 100 Day Celebration Ideas in a later post. Just click the link to get there!
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