Objective: Students will be able to add two-digit numbers within 20 correctly.

Materials Needed:

-mini whiteboards
-dry erase markers
-adding strips

Warm Up:

Write the following equation on the board:

14 + 6 =

Have students solve the equation using what they already know.

Guided Practice:

Pass out the adding strips to the students.

Explain how to use the strips to add two-digit numbers. Have students complete two addition equations on their strips.

Check for understanding.

Independent Practice:

Give students three equations, written on mini whiteboards, to solve:

1. 12 + 7
2. 17 + 3
3. 19 + 1

Have students come up to the board one-by-one to solve the equations in front of the class, using their adding strips. Check for understanding.

Conclusion:

Review the lesson by having students solve one more equation on their whiteboards. Check for understanding.

Assessment:

Have students complete a worksheet in which they add two-digit numbers within 20.