assess students' prior knowledge, gather the students in a circle
around a set of objects that have been sorted. You might select blocks
that are flat and round, pattern blocks that may be sorted by color,
multicolored connecting cubes, or cubes connected in long and short
Ask the students to name the rule that you used for
sorting--such as big and little, round and flat, red and blue, or long
and short--and provide labels for the various sorting rules the
students name. These labels might be printed on index cards to make
them easy to move about for different sorts.
Have the students return to their seats and record a picture
that matches a rule you used in the sorting activity, such as big and
little or round and flat, on the Student Learning Guide, Assessing Prior Knowledge activity sheet.
Depending on the age and ability of the students, you might have
them label their drawings with a rule. For older students, you might
provide labels printed on the paper and have the students draw a
picture that matches the rule.
To begin the lesson, gather the students as a whole group and
review the rules for sorting and classifying objects using the
recordings that the students made during the previous lesson, "Finding
Properties for Sorting".
Read the chart created in the previous lesson that lists the various properties used for sorting.
Compare the list with the properties used by the students in
this lesson, and add new ideas if the students proposed properties not
The students might recognize properties in this lesson that
were not apparent to them in the previous lesson. This indicates that
they have learned new ways to sort.
Ask the students to stay in their seats and identify properties
for sorting that are found around the room. Discuss the properties and
the rules for identifying them.
To develop the students' skills in observing for a common property, ask certain students to come to the front of the class.
Select the students by choosing a common property, such as all
wearing tennis shoes, all wearing clothing with stripes, all wearing
clothing with writing, all having blue eyes, or all who are
Once those with similar characteristics are standing, invite
the other students to name the sorting rule that you used. When the
students have correctly named your rule, discuss why other rules might
also be accurate.
It is important to acknowledge the keen observation skills of
young children because they will find unique patterns, such as the
students wearing broken buttons or the students wearing black shoes
Ask the students to explain how they arrived at their rules.
Defending answers is essential for building reasoning skills. It also focuses on observation of multiple properties.
Model the above procedure several times so that the students
fully understand how to look for and select a property common to all
the students in the group.
Have different students take turns choosing the rule, selecting
the students, calling on someone to identify the sorting rule, and so
Engage the students in discussing how they developed strategies to identify the patterns.
The Key Questions might be used at appropriate points to focus on the mathematics inherent in this activity.
Have the students draw a picture of a group of students
displaying a common property and write a one- or two-word title that
describes the sorting rule--for example, "Stripes," "Wearing Red,"
"Wearing Plaid," or "Blue Eyes." If appropriate, have the students
write a statement describing their picture.
Review these recordings to determine the students' current level of understanding.