Learning Intention: Students will be able to add two digit numbers within 20.

Materials: student white boards, base ten blocks, number sentence cards

Procedure:

1. Introduce the lesson by discussing strategies for adding two digit numbers within 20. Show the students a few models using base ten blocks and ask them to explain the process.

2. Ask the students to each get a student white board and a set of number sentence cards. Explain that the cards have problems on them that they will be solving utilizing different strategies.

3. Provide students with the concept that 10 can be thought of as 1 group and any numbers higher than 10 can be thought of as 1 group plus some extra. Show an example like 14 = 1 ten and 4 ones.

4. Ask students to work with a partner using their white board and set of number sentence cards.

5. Provide guidance as needed as the students work through the problems.

6. After the pairs have had a chance to attempt each problem, gather the class together and ask pairs to share the strategies they used.

7. Provide closure by summarizing the strategies used and the importance of understanding the concept of the number 10.