In this lesson, students share and critique strategies for adding two-digit numbers. They reexamine all of the strategies used in recent lessons, including arrow notation, quick tens, and number bonds. Examining various work samples, students compare for clarity, answering questions such as: Which drawing best shows the tens? Which drawings make it easier to not count all? Which number sentence is easiest to relate to the drawing? What is a compliment you would like to give [the student]? What is a way that [the student] might improve her or his work? How are [Partner A's] methods different from or the same as yours?