What is a Set?

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SWBAT use fractions to describe a set of objects.

Big Idea

Sets of objects are all around us and we can describe them using fractions


5 minutes

We have been working on fractions, but I know it’s Monday and I want to make sure what we have learned is fresh in our minds! Who can help me complete the board to review what we know? 

Here we discuss what we know about fractions and focus on key vocabulary. We discuss that fractions show us parts of a whole and we use the vocabulary part, whole, numerator and denominator in context. I want students to be familiar with the terms we use in fractions and to understand what they represent. 

Group Practice

10 minutes

You know how to write a fraction to describe part of a whole. Today we will be digging deeper into learning about using fractions to describe a set.

Invite 5 students to come to the front of the room. These five students form a set. How many parts does this set have? (5) (hold up 5 fingers) What is the name for each part? (Fifth) (have students repeat this with you. 

I use additional, contextual, questions to practice setting up problems correctly and understanding what it means to have parts of a set (our class) (MP4).

What fraction of students is wearing sandals?

Black shoes?

Repeat the activity a few times while asking students which is the part? Whole? Which is the numerator? Denominator? I want to reinforce the language of fractions and allow students to practice hearing it and saying it.

Group Work

30 minutes

I have this bag full of blue and yellow counters, and I’m wondering how many ways I can show what I have. Let me show you what I mean.

I have white paper folded into a 4 square and I take out, and show students, eight counters. Five are yellow and three are blue. What is this group called? (A set.) And what fraction of my counters are showing blue? What is my numerator? And my denominator? Which is the part? Which is the whole? And what about what it should look like in case someone wasn’t here and wasn’t sure how we can draw out our fractions?

Students work at their tables to create as many fractions of their set of counters as they can think of and record by writing a fraction, labeling or illustrating (MP1). For students who finish, I have bags full of manipulatives that they can classify and describe using fractions. I want student to have an extended opportunity to recognize that not all sets of objects have the same amount (or denominator) and there is not just one correct way to find fractions within sets (MP5).