**Lesson 2: Operations on Sets**

*Textbook Pages*: 16-40

*Suggested Number of Hours:*12 hours

**Lesson Objectives and the K to 12 Curriculum**

Learning Competencies

Learning Competencies

Lesson Objectives |
Learning Competencies |

• Define and describe the complement of a set
• Define and describe the union and intersection of sets • Use a Venn diagram to represent sets, subsets, and set operations • Solve problems involving sets |
The learner . . .
• illustrates the union and intersection of sets and the difference of a set. • uses Venn diagrams to represent sets, subsets, and set operations. • solves problems involving sets. |

**Essential Questions**

How can sets be combined?

**Technology and Resources**

*Math Ideas and Life Applications (MILA) 7 Textbook 2nd Edition*

**Materials**

chalk or marker, board

**Learning Plan**

**Introduction**

Discuss the lesson opener on page 16 to motivate the students. Ask if they can cite similar examples that deal with combining two objects to produce a new object of the same kind. Post the essential question “How can sets be combined?” on the board.

**Lesson Development**

1. Define and illustrate complement of a set (see page 17).

2. Discuss each of the following operations between two sets: union, intersection, and difference of sets. Give examples. Then let the students give their own examples to illustrate each set operation.

3. Have the students answer the following exercises from the textbook: all items in letter A of Establishing, and items 1 to 5 in letter A of Refining on page 30.

4. Discuss how the Venn diagram is used to represent set relations and operations (see pages 21–24). Give examples similar to those found on the said pages.

5. Define disjoint sets (see page 25) and give examples.

6. Discuss how to solve problems involving sets and Venn diagrams (see pages 25 to 29). Give several examples.

7. Have the students do the activity in Performance Task on page 36.

**Generalization and Assessment**

1. Have the students do the remaining exercises in Gauging What You Have Learned on pages 30 and 31: all items in letters B and C of Establishing, and items 6 to 10 in letter A and all items in letters B and C of Refining.

2. Assign the exercises in Intensifying as homework.

3. Ask the students to write on a sheet of paper their answer to the essential question.

**Answer Key to Gauging What You Have Learned**

**Establishing**

**Refining**

**Intensifying**