In a previous unit, students were introduced to Add To and Take From, Change Unknown story problems and solved these problems in any way that made sense to them. This lesson offers more practice making sense of and solving these types of problems. Students share different methods used and discuss how either addition or subtraction can be used to solve these problems. These discussions help students develop their understanding of how to make sense of and solve these problem types and reinforce their methods for adding and subtracting within 20.
If students need additional support with the concepts in this lesson, refer back to Unit 2, Section A in the curriculum materials.
Activity 2: Encontremos el número desconocido
- Solve Add To and Take From, Change Unknown story problems in a way that makes sense to them.
Materials to Gather