Lesson 2
Relacionemos contar con sumar
Lesson Purpose
The purpose of this lesson is for students to understand and apply counting on and the commutative property in order to find the sum.
Lesson Narrative
In a previous unit, students were introduced to the commutative property in the context of story problems. In this lesson, students consider and use different methods for adding within 10. They relate counting on to addition and consider how the commutative property can help them find the sum more efficiently. Counting on is a method which students use when they are ready, so they may count on for certain sums but count all for others. Students are not explicitly told to count on from the bigger number—this is an understanding that they come to through the work of this and future lessons in which they compare addition methods.
- Action and Expression
- MLR6
Learning Goals
Teacher Facing
- Understand and apply counting on as a method for addition.
- Understand and use the commutative property.
Student Facing
- Sumemos hasta 10.
Required Materials
Required Preparation
- Each student needs their addition expression cards from a previous lesson to use during the lesson synthesis.
Activity 1:
- Each group of 2 needs 10 two-color counters.
- Have one cup available to demonstrate Shake and Spill.
Lesson Timeline
| Warm-up | 10 min |
| Activity 1 | 15 min |
| Activity 2 | 10 min |
| Activity 3 | 10 min |
| Lesson Synthesis | 10 min |
| Cool-down | 5 min |
Teacher Reflection Questions
How does understanding the commutative property benefit students as they build fluency with addition within 10?