In this lesson, students find matching expressions to create true number sentences. They work solely with equations to show and talk about how they would rerepresent a given addition or subtraction problem using an advanced strategy. For example, when given 9 + 6, students decompose the 6 into 1 and 5 and then can add using their new number sentence, 10 + 5 (i.e., 9 + 6 = 10 + 5), using pictures and words.