Addition and subtraction - Fact families - Presentation

In an engaging mathematics lesson, students are introduced to the concept of fact families within the context of addition and subtraction. A fact family comprises related addition and subtraction sentences that involve the same numbers. For example, if 3 and 7 combine to make 10, then the fact family includes the sentences 3 + 7 = 10, 7 + 3 = 10, 10 - 3 = 7, and 10 - 7 = 3. The lesson encourages students to explore these relationships through various activities, such as discussing the connections between different flowers or stars, and considering the impact of changing the order in which numbers are added or subtracted. Visual aids like part-whole models and bar models are used to illustrate these numerical relationships, helping students to visualize the concept and write all associated number sentences for a given set of numbers.

The lesson progresses with exercises that challenge students to apply their understanding of fact families to different scenarios. They are asked to identify the parts and the whole within a model, and to write out all the number sentences that belong to the same fact family. Further reasoning activities prompt students to explore various combinations of numbers that fit within a certain range, and to evaluate statements for correctness, fostering critical thinking and problem-solving skills. Independent work tasks involve cutting out models and writing associated facts, as well as identifying incorrect representations, ensuring that students have ample opportunity to practice and consolidate their learning about fact families.