Learning Intention: By the end of this lesson students will be able to add two-digit numbers within 20.

Objectives: 1. Students will be able to identify and use the addition sign (+). 2. Students will be able to recognize and generate addition number sentences. 3. Students will be able to add two-digit numbers within 20 and give the correct answer.

Materials Needed: - Whiteboard/chalkboard - Dry erase markers and wipe board - Addition flashcards

Procedure: 1. Begin by discussing the addition sign (+) with the students and how to write addition number sentences. Explain that each number sentence needs two numbers that are being added together. 2. On the board, write an example of an addition number sentence (e.g. 10+8=). Give the students time to read and guess the answer before revealing it. 3. From here, have students answer questions like this one on the board. Generate a few more examples (15+5, 12+3, etc.) before returning to individual flashcards. 4. Using the addition flashcards, have students raise their hand when they are ready to answer the cards aloud. Ask students to explain their thinking process as they come up with their answers. - If multiple students have the same answer, ask for volunteers to explain the reasoning behind their answers. 5. When all students have answered the questions on the flashcards, ask the students to make up their own addition number sentences with numbers within 20 and solve them. 6. As a final task, have the students make up their own flashcard and share it with the class.

Closure: After all the practice, ask the class to explain what they just learned and why it’s important to be able to add numbers within 20. Ask for volunteers to share an example of an addition number sentence and ask the class to solve it.