Adding Three Numbers
Applying addition strategies to find the sum of three whole numbers whose sum is less than or equal to 20.
Key Questions
- Explain how you can group numbers to make adding three numbers easier.
- Predict if the order in which you add three numbers changes the total sum.
- Construct an example of adding three numbers using the 'make ten' strategy.
Ontario Curriculum Expectations
Suggested Methodologies
Ready to teach this topic?
Generate a complete, classroom-ready active learning mission in seconds.
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.
More in Operations and Algebraic Thinking
Addition Strategies: Counting On
Moving from counting all to using the 'counting on' strategy for addition within 20.
2 methodologies
Addition Strategies: Making Ten
Using the 'making ten' strategy to add numbers within 20, understanding number bonds to ten.
2 methodologies
Subtraction Strategies: Counting Back
Developing subtraction strategies by counting back from a given number within 20.
2 methodologies
Subtraction Strategies: Related Facts
Understanding the relationship between addition and subtraction to solve subtraction problems.
2 methodologies
Understanding the Equal Sign
Reframing the equal sign as a symbol of balance, representing that both sides of an equation have the same value.
2 methodologies