Here is the first one I did with my first block geometry class.
Students had several reasons why they chose their particular shape.
- "I think it is the hexagon since all of the other figures are triangles."
- "I think that it's the shaded in triangle because all of the others are not shaded in."
- I think that it is the triangle in the upper left hand corner because it looks smaller."
This allowed for my students to be able to justify and defend their answers. I told students beforehand that there was not one right or wrong answer as long as they could justify their answers.
I then gave this problem to my Algebra II class.
Here are some of the students' thoughts.
- I think that it is 9 because it is the only single digit number.
- I think that it is 43 because it is the only prime number.
- I think that it is 16 because it is the only even number.
- I think that it is 43 because 9, 16, and 25 are all perfect squares.
- I think that it is 43 because you can take the square root of 9, 16, and 25 and get a whole number
I want to say that I had so much success with this activity that I will definitely plan on using it again I even did a tweet out to the Math Twitter Blogosphere about it :)
So I encourage you to use this activity with your students. The website is Which One Doesn't Belong?
So, with that, I hope you have a great rest of your Thanksgiving Holiday and rest up strong for three more weeks until the Christmas/Winter Break!!!