Friday, March 30, 2012

Measurement: Perimeter and Area

Since atttending the Guided Math conference a couple of weeks ago, I'm on the hunt for this book. It's by Barbara Blanke and is called Number Connect for Grade 3. It's part of the Bridges series. Anyone use this or know where I could find it???

Barbara's seminar was great. She's all about just good solid math teaching that centers around problem solving and questioning. She encourages teachers to avoid "being the source of the truth or answers." Instead she recommends asking genuine interest questions. (She provided lists of question starters to help with this.) In her words, "Be a guide, on the side." I catch myself leading my kids too much sometimes. I'm working on setting up learning situations that will allow my students to make math discoveries. Barbara is a master at differentiation through questioning. Something I'm working on.

During her presentation she used a document camera to model her lessons. I recently purchased on with grade level funds. This one was only $113.00 through Office Depot. It works great through my smartboard. It had software that includes lots of tools like highlighters and pens and such. I'm still playing with it to figure it out but love it. (oops...probably shouldn't have that diet coke right beside all my tech equipment! Can't get through my pm slump without it!)

I recently used it for a lesson on perimeter. I was trying to channel Barbara through this lesson and so started with a question. I took one of these pentominoes and put it under the document camera. I displayed it and wrote by it: perimeter=12 units. Now they had not had any experience with perimeter so I asked them what they thought the perimeter might be. After some discussion with partners they discovered that if you counted around the shape it equaled the number 12.
From there we practice figuring the perimeter of other shapes of pentominoes using the document camera. Have you used pentominoes for teaching perimeter and area? We have a fantastic math specialist at our school and I have learned so much about good math instruction from her. This lesson idea is one she shared with us.
The next day, students worked to trace and determine perimeter and area of different shapes of pentominoes. I basically walked around trying to be "the guide on the side" , allowing students to make discoveries and steering their thinking with my questioning.
Students are working on proving answers. Here students showed their math thinking on papers.
Do you have ideas about teaching perimeter and area? Please share!


  1. those pentominoes are cool!!! I've never seen them

  2. I love the idea of guiding your students with questions. The perimeter lesson was great.Do you have any info about future conferences?

  3. I had never heard of Bridges until the other day. That's when I found this . It is for Bridges stuff and LOTS of it is free!! Not sure if what you are looking for is there or not, but worth a shot!

  4. Yes, the Math Learning Center is where that book came from. I have it - great activities. I have attended several workshops run by this group. Very well organized and terrific information.

  5. For area my students used cheese nips. They had to draw shapes and have their partners use the cheese nips to figure out the area. They loved it.. I do like your manipulatives too. Never saw them although I am new to teaching so that might explain it.