Conozcamos los algoritmos de suma
The purpose of this lesson is for students to use their knowledge of base-ten diagrams to make sense of two written addition algorithms.
In a previous lesson, students revisited addition within 1,000 using strategies based on place value, and properties of operations. An algorithm is different from a strategy because it is a set of steps that works every time as long as the steps are carried out correctly. The algorithms introduced in this lesson draw on the grade 2 work within 1,000 in that they show the addition of ones to ones, tens to tens, and hundreds to hundreds. Students should have access to base-ten blocks if they choose to use them.
Activity 1: ¿Qué es un algoritmo?
- Add within 1,000.
- Relate base-ten diagrams to written algorithms for addition.
- Aprendamos nuevas formas de sumar.
Materials to Gather
|Activity 1||20 min|
|Activity 2||15 min|
|Lesson Synthesis||10 min|
Teacher Reflection Questions
In grade 2, students spent significant time working with place value. How did students’ work with place value prepare them for the move to using algorithms to add?
- Target Numbers (1–5), Stage 6: Add Hundreds, Tens, or Ones (Addressing)
- Five in a Row: Addition and Subtraction (1–2), Stage 8: Add within 1,000 with Composing (Addressing)
- Rectangle Rumble (3–5), Stage 2: Factors 1–5 (Supporting)