## Monday, June 8, 2015

### Chart Paper is my friend

The end of another year has come and gone, bringing with it both joy and sadness.  I love the anticipation of a new year and starting over with a blank slate, but I'm sad to say goodbye to my students and especially to wipe my classroom clean of all of the learning that has taken place in the past 180 days!  One of my goals this year was to "Make Thinking Visible", so my room was filled with posters that we referred back to often, so it was a day of sadness when I took them down and sent them out to the recycling bin.

If you know me at all, you know I LOVE school supplies (with big puffy heart loves!).  Two of my must-have school supplies are chart paper and sticky dots.  The best type of chart paper are the big post-it note pads with grid lines, but those are really expensive, so I try to be conservative with those.  We can get cheaper chart paper for just a few dollars from our district warehouse, so I tend to use that for activities like Chalk Talk, etc.  I stock up on sticky dots in the Target dollar section at back to school time.  I used to have the students draw dots, but it really annoyed me when the dots were various sizes, so now I just buy the little smiley face stickers and be done with it. :)

Anyway, a few weeks ago, I asked a group of stat teachers on Facebook about their favorite activities that they use to illustrate statistical content and I shared two of my favorites.  One of the respondents asked me to share more details, so here ya go...

Sampling Distribution of Means

I did this activity with a copy of Random Rectangles, but next year, I may use my well-loved JellyBlubbers.  For this activity, my students used a random number table to select 3 rectangles at random, find the average area and graph it.  They repeated this 3 times per person to gather a lot of data.  Then they repeated with 10 random rectangles.  The groups then discussed how the graphs were similar and how they were different.  Over the years, I had done a similar activity with proportions (flipping a coin), but the rectangles made an impact, as evidenced by one student's work below:

I don't know about you, but when an activity sticks out in a student's mind, then it's a keeper for me!

Confidence Intervals

Over the years, I have often asked my students to create a confidence interval and graph it to illustrate the meaning of "95% confidence".  However, this year, I decided to use some of my sticky dots to help nail down a few other items.  Here, students tossed a Hershey's Kiss and recorded whether it landed on its base or not.  This was our first introduction to confidence intervals, so instead of using the CI formula, students used their sample data to find the standard error and draw the sampling distribution model based on their p-hat.  Then they used +/- 2 standard errors to create their first confidence interval.  The part that I did differently this was having them graph their point estimate (p-hat) first, then draw left and right to create the interval.  The idea that I was trying to push home was that the point estimate is in the exact center of the interval, so given any interval, they can find the point estimate and the margin of error.  For some reason, this is a difficulty of many students.  They can calculate 0.4 +/- 0.12, but if you give them (0.28, 0.52), they are stuck on how to find the p-hat and the MoE.  For the rest of the semester, this graph often came up in conversation when students were trying to figure out the relationship between the point estimate, margin of error, and the interval estimate.

How do you use chart paper in your classroom?
What are your go-to school supplies that you can't live without?
What are your favorite activities to teach/illustrate a concept?

GOSH!! each of these are a blog post in and of themselves!! Still in school, so not quite to the reflection stage, but here are some brief thoughts:

How do you use chart paper in your classroom? For groups to share out problems, for gallery walks where students attach postits with constructive comments, for balloon gore patterns, for table talks (one word/phrase in center and students brainstorm what they know)

What are your go-to school supplies that you can't live without? lots of the usual: chart paper, markers, scissors, glue sticks, red-yellow-green cups, plastic 8X10 picture stands.

What are your favorite activities to teach/illustrate a concept? Review stations, foldables (although I need more ideas of how to use in AP Statistics), GeoGebra explorations (especially for parametric equations), the CI activity you showed above, and the Rice University Sampling Distribution applet to name a few.

I'm so glad to see you back! You were my initial inspiration to start a blog so thanks. @ladsit76 (https://soar180.wordpress.com/)

statsmonkey said...

LOVE both of these activities! Never underestimate the power of the sticky dot. I'm a firm believer that students need to go low/no tech, roll up their sleeves, and 'play' with the data before taking the leap to tech simulations and modeling. Thx for sharing the activities!! Thanks for the blog...Like Lynn notes, you and a number of other fellow statletes are responsible for inspiring me to start my own. WooHoo!