Late last week we started to look at circumference. I started the lesson by reading the story, Sir Cumference and the Dragon of Pi. If you haven't read any books in the Sir Cumference series, you HAVE to! They are perfect for upper elementary and middle school students, and such a great way to integrate reading into math. My students love these books. (I've included a link to Amazon below so you can check it out).
We then started our journal entry. To make the circles, I gave the students two different strips of paper. They taped the strips together to make circles, then dipped the circles in paint to make two different circle stamps on their paper. After the paint had dried, they taped the strips to their journals.
We measured the diameter of the circles, then measured the length of the strips (which we discussed would be the circumference of the circle). On their own, the students figured out that circumference is about 3x the diameter of a circle (in our curriculum, "pi" isn't discussed until grade 7). We added this information, our "big idea" under a sticky note on our journal page.
In our "proof", I asked the students to draw a different circle, and find the diameter and circumference of the circle. For our reflection, I used the Math Reflection Fans and chose the question, "What other math can you connect this to". This entry was so much fun - and the students couldn't believe we were actually using paint in math class!
Now, on to time ... I wanted to combine two of our expectations, elapsed time and the 24-hour clock, so the students would have something to refer to for our upcoming lessons.
We made a clock for our math journals for this entry. We used small paper plates for our clocks, but if you don't have any paper plates, you could easily use paper circles instead. We divided our circle into twelfths (snuck a little bit of fractions in there), and labelled our clocks (hours and minutes). We then cut a small strip at the edge of each section so we could fold over the flaps. On the back of the flaps, we wrote the 24-hour times. We made hour and minute hands, and attached them to the clock with a brass fastener.
With our clocks, we practiced telling the time with the 24-hour clock, and then I gave them some elapsed time questions (I have more lessons on both planned for this week). For the proof, I asked them to create and solve a problem related to elapsed time, and I challenged them to answer in both analog time and 24 hour time (most only answered one way, though). I used my reflection fans again to choose a reflection question - I made it easy on them today and asked them, "When could you use this math outside of school? Explain."
Well, that's it for today ... I've got to get back to my report cards. Wish me luck!!!