Perimeter and Area - Perimeter on a Grid - Starter

In a mathematics resource designed for Year 5 students during the Autumn term, the concept of perimeter is explored through engaging activities. The resource begins with 'Fluent in Four - Revision', a series of arithmetic problems aimed at sharpening students' skills in subtraction and mental arithmetic. For instance, students are challenged to find the missing number in the equation "838 – ? = 349", and to subtract half of 644 from a given number. These exercises serve as a warm-up to the main topic of the day, which is calculating the perimeter of various shapes.

The core of the lesson involves measuring the perimeter of a shape presented on the resource. Students must determine the perimeter in millimetres, with the shape's sides given in a mix of millimetres and metres. For example, one side might be 21 metres, while another is 32 millimetres, requiring students to convert between units of measurement. Additionally, the resource provides exercises that reinforce the concept of checking addition through subtraction. In one exercise, students verify the sum "3,795 + 5,971 = 9,766" by performing the inverse operation. The lesson also includes a task where students write a given number, such as 0.16, as both a fraction (16/100) and a decimal, enhancing their understanding of numerical representations.