Learning Objective: At the end of this lesson, students should be able to add two-digit numbers within 20, including the related concepts of ones, tens, and tens complements.

Materials: Whiteboard, markers, Smartboard.

Procedures:

1. Teacher Introduction: Before we begin, let’s review what we have learned so far. Who remembers what a number is? (Take responses). A number is a numerical representation of a certain quantity. Great job!

2. Introduce Learning Intention: Today, we are going to learn how to add two-digit numbers within 20. So our learning intention is that “At the end of this lesson, students should be able to add two-digit numbers within 20, including the related concepts of ones, tens, and tens complements”.

3. Explain the concept of ones and tens: First, let’s talk about the concept of ones and tens. Ones are single digits that represent the basic counting unit. Tens are two-digit numbers that represent a group of 10. (Draw a visual representation of this on the board).

4. Introduce Tens Complements: Now, let’s talk about the concept of tens complements. Tens complements are the numbers we need to add to a number to make it 10. For example, if we are adding 7+8, we need a 2 as a tens complement to make the addition work. Let’s try it. (Draw a visual representation of this on the board).

5. Guided Practice: Let’s practice some examples together. (Write different 2-digit numbers on the board and ask students to find the tens complements. Give them time to work in pairs and discuss their answers).

6. Independent Practice: Now, let’s do some more practice but on our own this time. (Hand out two worksheets with 2 digit addition problems and ask students to complete them).

7. Review: (After students have completed their worksheets, ask them to come to the board and explain the problems they solved). Great job! I can see that you all understand the concept of adding two-digit numbers within 20, including the related concepts of ones, tens and tens complements.