Learning Intention: To be able to add two-digit numbers within 20.

Overview: In this lesson, students will learn how to add two-digit numbers within 20 and why it is important to understand this skill.

Objective: At the end of this lesson, students should be able to add two-digit numbers within 20 accurately and explain why it is important to understand how to do this.

Materials needed: Pencils, paper, whiteboard/chalkboard.

Time: 30 minutes

Introduction (5 minutes): The teacher will introduce the topic by asking students why knowing how to add two-digit numbers is important.

Activity (15 minutes): The teacher will begin the activity by modeling an example of how to add two-digit numbers on the board/whiteboard. For example, the teacher will start by adding 12 + 8. The teacher will then have the students practice adding two-digit numbers with their partner or in groups. The teacher can provide the students with scenarios or questions for them to practice with.

Conclusion (10 minutes): The teacher will review the concepts with the students and ask them to explain why it is important to understand how to add two-digit numbers. The teacher will then ask students to answer any questions they may have.

Assessment: The teacher can assess student understanding by having them complete a practice worksheet or quiz.