Learning Intention: Students will be able to add 2-digit numbers with sums up to 20 correctly, demonstrating mastery of their mental math abilities.

Materials: dry erase boards, dry erase markers, crayons, paper, pencils

Lesson:

1. Introduce the lesson by getting the class to raise their hands if they can name two digit numbers up to 20 (eg. 10, 15, 17, etc).

2. Explain to the class that today they will be practicing their mental math skills by adding two digit numbers within 20.

3. Write two digit numbers up to 20 on the board and have the class take turns coming up to the board and adding them.

4. Give the class a paper and pencil and have them practice adding two digit numbers within 20. Demonstrate the process of adding the numbers on the board and explain the importance of carrying and borrowing when necessary.

5. Provide the class with dry erase boards and markers and have them practice adding the two digit numbers written on the board.

6. Discuss the importance of mental math and how it can help them learn math faster in the future.

7. Give the class a quiz on the material to assess their understanding.

8. Allow some time for the class to practice and ask questions if they have them.

9. Finishing the lesson by having the class draw a quick picture (using crayons) of themselves adding two digit numbers within 20.