Finding the Unknown in Equations
Solving for the unknown whole number in addition and subtraction equations within 20.
Key Questions
- Predict what number makes the equation 7 + ? = 10 true.
- Construct an equation with an unknown number that equals 12.
- Explain different strategies for finding the missing number in an equation.
Ontario Curriculum Expectations
Suggested Methodologies
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Planning templates for Mathematics
5E Model
The 5E Model structures lessons through five phases (Engage, Explore, Explain, Elaborate, and Evaluate), guiding students from curiosity to deep understanding through inquiry-based learning.
unit plannerMath Unit
Plan a multi-week math unit with conceptual coherence: from building number sense and procedural fluency to applying skills in context and developing mathematical reasoning across a connected sequence of lessons.
rubricMath Rubric
Build a math rubric that assesses problem-solving, mathematical reasoning, and communication alongside procedural accuracy, giving students feedback on how they think, not just whether they got the right answer.
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Developing subtraction strategies by counting back from a given number within 20.
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Understanding the relationship between addition and subtraction to solve subtraction problems.
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Understanding the Equal Sign
Reframing the equal sign as a symbol of balance, representing that both sides of an equation have the same value.
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