In previous lessons, students learned that decomposing a ten is sometimes necessary when subtracting two numbers. Students used connecting cubes and base-ten blocks to represent their methods when subtracting a one-digit number from a two-digit number.
In the fist activity, students use methods that make sense to them to subtract and compare their methods with a partner. In the activity synthesis, students make connections across different methods and representations and consider which tools and representations work best for them. In the second activity, students use base-ten blocks to represent expressions and decompose a ten when subtracting by place.
Students should have access to connecting cubes and base-ten blocks throughout the lesson and the cool-down.
- Subtract a two-digit number from a two-digit number in a way that makes sense to them.
- Hagamos restas con números de dos dígitos.
- Create a set of cards from the blackline master for each group of 4.
|Activity 1||15 min|
|Activity 2||20 min|
|Lesson Synthesis||10 min|
Teacher Reflection Questions
- Capture Squares (1–3), Stage 3: Add within 20 (Addressing)
- Five in a Row: Addition and Subtraction (1–2), Stage 6: Add within 100 with Composing (Addressing)
- Target Numbers (1–5), Stage 4: Subtract Tens or Ones (Addressing)
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|