Sumemos y restemos de formas diferentes números de tres dígitos
In previous lessons, students used what they know about counting within 1,000 and place value to subtract multiples of 10 and 100 from three-digit numbers. In this lesson, students continue to apply methods they used when adding and subtracting within 100 to add and subtract within 1,000. They also make sense of methods that are represented with equations. In the first activity, they make sense of different methods for subtracting a three-digit number from a multiple of 100. In the second activity, they make sense of methods based on adding by place. Students are invited to try the methods for adding and subtracting that they analyze in this lesson or choose any method that makes the most sense to them. They will continue to analyze and use methods based on adding and subtracting by place in upcoming lessons.
- Action and Expression
Activity 1: Cero decenas y cero unidades
- Add and subtract numbers within 1,000 using strategies that do not include composing or decomposing tens or hundreds.
- Sumemos y restemos números de tres dígitos.
Materials to Gather
|Activity 1||20 min|
|Activity 2||15 min|
|Lesson Synthesis||10 min|
Teacher Reflection Questions
- Five in a Row: Addition and Subtraction (1–2), Stage 6: Add within 100 with Composing (Supporting)
- How Close? (1–5), Stage 3: Add to 100 (Supporting)