Where Should Pi Go?

I'm up early on a Saturday morning so I can catch up on blogging/Twitter. I have to say, I've been blessed with a child that likes to sleep in (I know!)... don't hate me too much, she still isn't sleeping through the night at 14-months. I was definitely up at least 3 times last night, oh joy.

Anyway... I just want to say, I love blogging and Twitter for stretching my thinking! Seriously!

Again, Sarah Hagan has given me some blog traffic! (thanks, Sarah!) I checked my stats this morning and saw another older post about Pi Day Decorations was getting some new views. I love that Sarah took my idea and made it look even better making a downloadable sign. If you notice, in the original picture, mine is just hand drawn... probably because I thought of it approximately 2.5 seconds before students were coming in! Not that I'm always a procrastinator, but here's why I decided to do it: The day before I did a math talk where I asked students to put pi on a number line. We discussed as a class. This was VERY tough for my students (as I anticipated). You see, many have the belief that a "long" number is a "large" number. This misconception is the result of making sense of whole numbers when they are in elementary school, but not making sense of parts of numbers/decimals. So after the math talk, and finally getting pi in the correct location on the number line, I wanted to reinforce this in my classroom. That is why pi landed where it did by my clock.

(maybe it should be a little closer to 3)


Well, that was back on Pi Day 2014... I haven't really though about it too much. Now, enter Sarah's blog post and the comments to said blog post! I hope Sarah doesn't mind, but I took a screen shot so I could share and discuss:
Ah, so, according to Frank, the clock should be a unit circle! So cool because it got me thinking! Of course, for my middle schoolers, it wouldn't really make much sense yet, but in a high school classroom, I could totally see this.

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Okay, speaking of clocks and pi. Maybe this is the post to discuss 2 clocks that I've seen on social media. Many friends have tweeted or put on Facebook these clocks... while I think the idea is SUPER CUTE, I do have an issue with how pi is used in the clocks.

Here is the first one:

Notice where "9" should be? Well, if you do pi-.14, they are assuming you will get 3, which will then be multiplied by 3 and therefore 9. But here's the issue: pi-.14 = 3.00159265358979323.... In other words, not 3.

Here's the second clock with a similar issue:
This time, the same mistake is at 3. Pi-.14 is not exactly 3.

Okay, I think that's enough for this post about pi and clocks! Thanks #MTBoS for a fun start to my Saturday! :)

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