Restemos hasta 1,000
The purpose of this lesson is for students to choose methods for finding the value of differences based on the numbers being subtracted.
In previous lessons, students found subtracted using various methods and representations with an emphasis on strategies based on place value. They analyzed numbers to anticipate whether they may need to decompose one or more units to subtract.
In this lesson, students attend to the relationship between numbers in expressions to flexibly subtract. Although the focus of this section has been on interpreting and using methods based on place value, the number choices in this lesson are intended to also encourage the strategies students used in prior sections. Throughout this lesson, students explain their thinking and listen to and critique the reasoning of others (MP3).
- Subtract numbers within 1,000 using strategies based on place value and the properties of operations.
- Restemos de una manera que tenga sentido.
Materials to Gather
|Activity 1||15 min|
|Activity 2||20 min|
|Lesson Synthesis||10 min|
Teacher Reflection Questions
How are students using their understanding of number relationships and place value to choose their methods for subtracting? What more can be done to help students recognize and plan for the units they need to decompose when subtracting by place?
- Target Numbers (1–5), Stage 5: Subtract Two-digit Numbers (Supporting)
- Number Puzzles: Addition and Subtraction (1–4), Stage 4: Within 100 with Composing (Supporting)