Number Bonds to 20Activities & Teaching Strategies
Active learning is essential for number bonds to 20 because it moves students beyond simply memorizing facts to truly understanding number relationships. Hands-on exploration and collaborative discussion allow students to discover patterns and build fluency with addition and subtraction facts within 20.
Number Bond Match-Up: Cards
Create sets of cards, with one card showing a number (e.g., 13) and others showing pairs that sum to it (e.g., 10+3, 9+4, 8+5). Students work in pairs to match the number cards with their corresponding bond cards.
Prepare & details
Compare number bonds to 10 with number bonds to 20.
Facilitation Tip: During the Think-Pair-Share, give students quiet time to first consider the number bond cards individually before they discuss with a partner.
Setup: Standard classroom seating; students turn to a neighbor
Materials: Discussion prompt (projected or printed), Optional: recording sheet for pairs
Building Towers: Number Bonds
Provide students with two colors of building blocks. Ask them to build towers of a specific height (e.g., 15 blocks) using only two colors. They record the number of blocks of each color used, creating a visual representation of a number bond.
Prepare & details
Construct all possible number bonds for the number 15.
Facilitation Tip: During the Jigsaw expert phase for Building Towers, circulate to ensure each group is focused on understanding the specific number bond they are assigned to become experts on.
Setup: Standard classroom seating; students turn to a neighbor
Materials: Discussion prompt (projected or printed), Optional: recording sheet for pairs
Number Bond Hopscotch
Draw a hopscotch grid with numbers up to 20. Students hop to a number, then call out two numbers that add up to it. For example, landing on 17 might elicit '10 and 7' or '9 and 8'.
Prepare & details
Justify why knowing number bonds helps with addition and subtraction.
Facilitation Tip: During Number Bond Hopscotch, prompt students to articulate their number bond choices aloud as they land on each number, encouraging them to think about different combinations.
Setup: Standard classroom seating; students turn to a neighbor
Materials: Discussion prompt (projected or printed), Optional: recording sheet for pairs
Teaching This Topic
To teach number bonds to 20 effectively, use a concrete-to-representational approach. Start with manipulatives like blocks or counters, then move to pictorial representations like number bond diagrams or number lines. Emphasize the part-part-whole relationship and encourage students to articulate their thinking, making connections to known facts from number bonds to 10.
What to Expect
Students will be able to identify and articulate multiple ways to represent numbers up to 20 as sums of two addends. They will demonstrate flexibility in their thinking, seeing the connections between different number bonds and understanding how they relate to each other.
These activities are a starting point. A full mission is the experience.
- Complete facilitation script with teacher dialogue
- Printable student materials, ready for class
- Differentiation strategies for every learner
Watch Out for These Misconceptions
Common MisconceptionDuring Number Bond Match-Up, watch for students who only identify one pair of numbers that sums to a target number, like only 10 + 5 for 15.
What to Teach Instead
Redirect students by asking them to find 'another pair' or 'a different way' to make the number using the remaining cards or by drawing more combinations.
Common MisconceptionDuring Building Towers, watch for students who struggle to connect the height of the tower (the whole) to the two different colored blocks (the parts).
What to Teach Instead
Guide students to physically separate the tower into its two color components and then write the corresponding addition and subtraction sentences, reinforcing the relationship.
Common MisconceptionDuring Number Bond Hopscotch, watch for students who only call out addition facts and struggle to see the subtraction relationship.
What to Teach Instead
Prompt students to say 'and also' or 'which means' after they state an addition bond, encouraging them to immediately follow with the related subtraction fact (e.g., '9 + 6 is 15, and also 15 - 6 is 9').
Assessment Ideas
After Number Bond Match-Up, observe which pairs students correctly match and listen to their explanations for why the pairs work.
During Building Towers, ask students to explain to a partner how they know their tower of blocks represents a specific number bond, using terms like 'whole,' 'part,' and 'add.'
After Number Bond Hopscotch, have students write down two different number bonds for a number you provide (e.g., 17) on a slip of paper before leaving.
Extensions & Scaffolding
- Challenge: Ask students to find number bonds for numbers between 10 and 20 using three addends.
- Scaffolding: Provide partially completed number bond diagrams or fact families for students who need more structure.
- Deeper Exploration: Have students create their own hopscotch grids or matching games for number bonds to 20.
Suggested Methodologies
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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