Learning Intention: Students will be able to accurately add 2 digit numbers within 20.

Step 1: Introduction (5 minutes) Today, we’re going to practice adding two-digit numbers within 20. Let’s start by reviewing some key concepts. What’s a two-digit number? (Allow students to respond.) That’s right, a two-digit number is any number that is made up of two digits, such as 17, or 11.

Step 2: Teacher Modeling (5 minutes) Let’s look at an example: Let’s say you had to add together 15 and 7. What would you do? I’m going to show you one way you can do this using a numbered diamond.

Draw a numbered diamond on the board with the numbers 15 and 7 on either side. Demonstrate how to use the numbered diamond to add the two numbers together.

Step 3: Guided Practice (10 minutes) Now, let’s practice some sums together.

Pass out a worksheet of two-digit addition problems for students to complete. Walk around the room and offer help as needed.

Step 4: Individual Practice (15 minutes) Now, let’s try adding two-digit numbers on our own. Here is a worksheet of two-digit addition problems for you to complete.

Distribute a worksheet of two-digit addition problems for students to complete individually.

Step 5: Conclusion (5 minutes) Let’s finish up by reviewing what we’ve learned. What strategy did we use to add two-digit numbers? (Allow students to respond.) That’s right, we used the numbered diamond strategy. Remember to use this strategy when you’re adding two-digit numbers within 20.