Subtraction Algorithms (Part 1)
In previous lessons, students revisited subtraction within 1,000 using strategies based on place value, properties of operations, and the relationship between addition and subtraction. In this lesson, students are introduced to a subtraction algorithm that clearly shows the subtraction of ones from ones, tens from tens, and hundreds from hundreds, and is similar to one of the initial addition algorithms in a prior lesson. Students should have access to base-ten blocks as needed.
- Relate base-ten diagrams to written algorithms for subtraction.
- Let’s learn a new way to subtract.
Materials to Copy
- Diagrams and Algorithms
- Create a set of cards from the blackline master for each group of 2.
|Activity 1||15 min|
|Activity 2||20 min|
|Lesson Synthesis||10 min|
Teacher Reflection Questions
Reflect on how comfortable your students are asking questions of you and of each other. What can you do to encourage students to ask questions?
- How Close? (1–5), Stage 4: Add to 1,000 (Addressing)
- Number Puzzles: Addition and Subtraction (1–4), Stage 5: Within 1,000 (Addressing)
- Five in a Row: Multiplication (3–5), Stage 2: Factors 1–9 (Supporting)
Print Formatted Materials
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|Student Task Statements||docx|
|Lesson Cover Page||docx|
|Cool Down||Log In|
|Teacher Guide||Log In|
|Teacher Presentation Materials||docx|