Perimeter and Area - Perimeter of Rectilinear Shapes - Planning

In a Year 5 mathematics lesson focused on the measurement of area and perimeter, students are introduced to the concept of calculating the perimeter of rectilinear shapes. This lesson moves away from the use of squared paper and challenges students to use their addition and subtraction skills to find missing side lengths. The class begins with a starter activity that involves a recap of previous learning and a discussion about the properties of rectilinear shapes. The children are then presented with shapes where some side measurements are not shown, prompting them to use the given dimensions to work out the missing lengths. Key vocabulary such as centimetres, metres, equivalence, perimeter, lengths, add, and subtract is emphasised, and resources such as worksheets and presentations are provided to support the learning process.

During the lesson, the term 'equivalence' is revisited, and students are shown how to use this concept to calculate missing sides, and ultimately, the perimeter of the shape. For instance, if a side is missing and the children know the total length of the opposite side, they can use addition to find the missing measurement. Partner work encourages collaborative problem-solving and the application of these methods to various rectilinear shapes. The lesson also includes differentiated activities, where children at different levels of understanding can practice finding one or two missing lengths, working with centimetres or adding the complexity of millimetres. Key questions prompt critical thinking about the importance of opposite sides and how to use part-whole models to solve perimeter problems. The lesson ends with a reflective 'Give me five' activity, where students assess their understanding and the skills they employed or found challenging, ensuring they remember the day's key learning points.