Lesson 9

The purpose of this lesson is for students to compare, connect, and solve story problems.

In previous lessons, students solved all the types of story problems including Add To, Take From, Put Together, and Compare with the unknown in all positions. The purpose of this lesson is to sort a variety of story problems, including two-step problems, and choose a problem to solve. Students sort the story problems and describe the categories they create. They then choose to solve the story problems using a method that makes sense to them. This lesson can be used to assess how students think about and make sense of story problems and the methods and representations they are most comfortable using to solve them (MP2).

Students work with story problems within 100 to reinforce the fluency expectation for grade 2.

• Create a set of cards from the blackline master for each student.

The standards suggest using the relationship between addition and subtraction as one way of solving problems. How do tape diagrams support students in seeing this relationship within a problem? How can you help students continue to make these connections?