WMS: Friday's Math play-by-play... and calculators!

Dear Families,

This is Friday's edition of our math play-by-play. I really just wanted to help everyone know what was happening on a daily basis here at the beginning of Semester 2. These messages are archived at my blog (http://www.mrmacnevin.com) and you can also find more information there about the class.

Students should bring their calculators

Oh! And about calculators! It is time for students to make sure they have a calculator with them. It needn't be a fancy one, but I ask that you or your student label the calculator and the case (if it has a removable case). We won't use them all the time (the state test in the spring doesn't allow them). But we are moving into talking about the area of a circle today and I just don't find it reasonable to ask students to square radii and then multiply it by pi all by hand. As with the MSP, there will be some specially selected problems when their hand calculation methods will let them do it quickly, but for practical day-to-day (okay, so real-life) uses, the calculator will be much more empowering. We will avoid using the π button on the calculators, however, since students are expected to be able to use the decimal and fraction approximations of pi (3.14 and 22/7). 

Where is Wednesday's Area and Perimeter Quiz?

I tried really hard to finish scoring their quizzes during the week, but I'm afraid I didn't meet that goal. Students will get their quizzes back on Monday, but their scores will be posted to Zangle over the weekend. Any 1's (beginning) or 2's (practicing) need to be retaken. Anyone scoring a 3 (proficient) may also retest for a 4 (advanced). Remember, as our first summative assessment in math of the semester, these quizzes may swing the grade wildly because they comprise 80% of the gradebook program's estimated grade. But any and all assessment scores can be retested. The goal is not perfection on the first try, the goal is improvement after someone uses their score to know what they need to go learn and practice.

Happy Friday! And a happy weekend!

Sincerely,

Brian MacNevin

Friday's Math Play-by-Play:

• MR Quiz: Today we had a math review quiz (4 questions). The questions were based on the questions that students had been working on in their math reviews all week. Following the quiz, we scored them together and I need to get those entered into the gradebook today so that they can come home on Monday. 
• Topic: Area of circles. Over the last two days we have talked about and practiced finding the circumference of circles (and of shapes based on circles). But today we extended that to talk about the area of circles. Before giving students the formula, I asked them to find out how many squares based on the radius (we called these radius squares) it took to fill a circle. We found that you can fit three radius squares and a little bit more (see a picture here: link). That's kind of like how many diameters fit around the outside of a circle: three and a little bit more. It turns out, that little bit more is about 14/100 of the diameter (or about 14/100 of the radius squares).. or 3.14 (pi)!
  Ka-chow! (What can I say, my son loves the Cars movie).
  So the area of a circle is A = π x r x r (or A = π x r² ). Students have a packet to practice the calculations and also to try it out with some fun applications. They didn't have time to work on it much in class today and we will finish it on Monday.
• Homework: No homework assigned for the weekend. The area packet in their math notebooks we will finish on Monday.