Solve add to with result unknown and put together with result unknown math stories by drawing, writing equations, and making statements of the solution.

In this lesson, students solve two types of word problems: "add to with result unknown" (for example, "There are 4 students dancing at a party. After a little while, 1 friend came along and joined the party. How many students are dancing at the party now?") and "put together with result unknown" (for example, "5 students were sitting, and 2 students were standing. How many students were there altogether?"). The lesson ends with a discussion in which students reflect on connections between these two problem types, recognizing that they use the operation of addition to solve both.