Unit 8, Lesson 3
Add and Subtract within 20
Grade 1
Preparation
Lesson Narrative
In previous lessons, students practiced adding and subtracting within 10. In this lesson, students use the methods that make the most sense to them to add and subtract within 20. The lesson activities encourage students to use methods such as using known facts, making 10 to add, decomposing a number to lead to a 10 to subtract, and using the relationship between addition and subtraction. This lesson helps students practice adding and subtracting with 20. Students also apply their fluency within 10 to prepare for their work with addition and subtraction in grade 2.
If students need additional support with the concepts in this lesson, refer back to Unit 3, Sections C and D in the curriculum materials.
- Engagement
- MLR8
- Present (using words and other representations) and compare and contrast strategies for adding and subtracting within 20.
- Let’s add and subtract within 20.
Required Materials
Required Preparation
None
Suggested Centers
NoneTeacher Reflection Questions
Reflect on your experience with the Number Talks in the curriculum. What moves or questions have improved the learning for each of your students during this routine? What improvements would you make next year to help all students develop fluency throughout the year?