Addition and subtraction within 20 - Related facts - Planning

In Year 1, during the third week of Spring term's focus on addition and subtraction within 20, students delve into the concept of related facts. The lesson utilises differentiated worksheets, teaching slides, and visual aids like the part-whole and bar models to facilitate understanding. The key vocabulary for this session includes 'inverse' and 'related facts', terms that are crucial for grasping the relationship between addition and subtraction. Through practical activities, children are encouraged to explore these relationships by constructing addition and subtraction sentences from given images and models. For example, they might be shown a part-whole model and asked to write corresponding number sentences, ensuring they grasp that subtraction is not commutative and that the whole cannot be subtracted from a part.

The lesson is structured to cater to various levels of ability, from working towards expected outcomes to achieving greater depth. As part of their independent learning, children are tasked with completing 'fluent in four' questions, which prompt them to use addition and subtraction skills to fill in missing numbers in bar models and to create related number sentences. In the plenary, students reflect on what they've learned, discussing the skills they've utilised and any challenges they've faced. This reflection is structured as a "Give me five" activity, where students use their fingers to represent different aspects of their learning, such as what new facts they've discovered, what they've understood, and what they promise to remember from the lesson. The goal is for students to identify patterns and understand the inverse relationship between addition and subtraction, enabling them to confidently work with numbers within 20.