Addition and subtraction - Find and make number bonds - Presentation

In Lesson 21(R), students are invited to revisit the concept of number bonds, focusing on those that sum to 10 and 20. This foundational mathematical skill is essential for understanding addition and the composition of numbers. The lesson encourages a systematic approach to finding all possible combinations, which is crucial for developing fluency in addition facts for larger numbers. Through a series of activities, students are prompted to discuss and explore various strategies to ensure that they can identify all number bonds within the given parameters. Visual aids such as counters and Lego pieces are used to represent these number bonds, helping to bridge the gap between concrete and abstract understanding.

The lesson progresses through a set of carefully structured activities that allow students to find and make number bonds using both counters and Lego pieces. By filling in the blanks for given scenarios, they practice creating addition sentences that form the desired number bonds. Additionally, the lesson includes reasoning tasks where students use equipment to represent calculations, compare different number bonds, and correct mistakes in part-whole models. Towards the end of the lesson, students are challenged to prove whether there are half as many number bonds to 10 as there are to 20, fostering critical thinking and problem-solving skills. Independent work further solidifies their understanding, asking them to use ten frames and explain their reasoning behind the similarities and differences in number bonds.