Unit 3, Lesson 19
Métodos para sumar hasta 20
Grado 1
Preparation
Lesson Narrative
In previous lessons, students decomposed an addend in order to make a ten and thought about sums as equivalent expressions. They applied the commutative and associative properties to find the sum more easily. Students looked for and used patterns in addition expressions, such as . In this lesson, students continue adding within 20.
Students may use any method they choose, but they are encouraged to think about methods which may work better for certain sums. In the first activity, students analyze three different methods for finding a sum, all of which include decomposing an addend to make a known sum. In the second activity, students find sums within 20 and share their thinking with a partner.
- Action and Expression
- MLR8
- Explain (orally and using words or other representations) strategies for adding within 20.
- Interpret (orally and using words or other representations) strategies for adding within 20, including those based on properties of operations and creating equivalent but easier or known sums.
- Sumemos hasta 20.
Required Materials
Required Preparation
- Each group needs a set of the Compare Stage 2 Addition Cards cards from the previous lesson.
Suggested Centers
NoneTeacher Reflection Questions
What methods are students using to find sums? Which methods were you expecting and which surprised you?