SWBAT explain their reasoning for the ways in which they group sets of objects.

Students begin to classify objects when they are very young, but can they define the attributes for the groups that they make?

10 minutes

I begin today by drawing a series of pictures on the Smart Board. I draw a kite, a balloon, a hot air balloon, an airplane, a smiley face and a sun. (I am no artist but I draw my outlines enough that students know what I am drawing.) I ask the children what the pictures have in common. I tell students that they can group just 2 things together, or 3 or all. A child might group the balloon, sun and smiley face because they are all round. I take 5 or 6 explanations of what students see as commonalities. I expect that students will notice function of the objects, similar shapes, beginning letters of the names of the objects, etc. . I have them point out the things they notice. I am hoping that students can think flexibly and notice more than one way to group the objects and explain why they grouped those objects together (construct a viable argument for why certain things can go together - MP3)

20 minutes

I tell students that today they will be looking at several shapes and each person will have a turn to group some of the shapes based on a single attribute. The rest of their group will try to figure out that attribute.

I pass out 9 shapes to each group. The shapes include regular squares, rectangles and triangles, some shapes colored in and others that are plain, and a series of shapes that are similar to squares, triangles or rectangles but have at least one curved edge.

I circulate around the room during the activity to listen to the kinds of classifications that students are using.

20 minutes

I give students old magazines and a large piece of paper. I ask them to draw 3 large circles on the paper. I show them how the 3 circles will overlap to make a Venn diagram. I tell students to pick 3 attributes such as a color, a shape, a size or a purpose (something to write with, etc.). I ask students to cut out pictures that have some of attributes they have labeled.. If the picture they cut out has all 3 attributes, they would place it in the middle where the circles overlap, if it only has one of the attributes it would go in that circle only. If it has 2 of the attributes it would go in the overlap of those 2 circles.

I demonstrate this and then when students have no more questions I let them begin their own attribute pages. I circulate around listening to the kinds of attributes that the students are finding and to watch how they are sorting their pictures.