What You’ll Learn: In this lesson, you will learn to add two digit numbers within 20.

Objective: At the end of the lesson, students should be able to add two digit numbers within 20 accurately.

Materials Needed • Pencils • Worksheets

Warm Up: (5 minutes) Review adding numbers within 10. Have students practice solving addition problems with one-digit numbers.

Activity 1: (15 minutes) Introduce two-digit numbers by writing an example of adding two 2-digit numbers on the board. Have students solve the problem, then offer guidance or ask questions to support their understanding.

Next, have students draw a number line from 0 to 20, then use the number line to solve problems. For instance, if the problem “15 + 7 = ?” is presented, point to the marker for 15 on the number line and explain that the answer is found by counting seven more numbers from 15.

Activity 2: (10 minutes) Distribute the worksheets and have students complete the problems. Make yourself available to answer any questions the may have.

Conclusion: (5 minutes) Discuss with the class what you’ve learned about adding two-digit numbers within 20. Check for understanding by asking for student volunteers to come to the board and solve a problem.

Review: Assess student understanding by giving a quiz or online assessment.