AC9M4M02 Year 4 Mathematics

Content descriptor recognise ways of measuring and approximating the perimeter and area of shapes and enclosed spaces, using appropriate formal and informal units

Elaborations

• • Elaboration recognising that perimeter is the sum of the lengths that form the boundary of a shape or enclosed space; choosing suitable units from a range of objects to measure around the boundary of a shape such as a garden bed; comparing the results to say which unit was an appropriate choice for the context; using a piece of string or rope to measure the perimeter of irregular shapes and enclosed spaces, including those that have curved sections
• • Elaboration creating a range of rectangles representing “paddocks” on grid paper and establishing different methods of working out the length of the boundary fences; explaining that the more efficient methods involve adding the side lengths rather than counting squares
• • Elaboration recognising that area is the space enclosed by the boundary of a shape or the surface of an object; measuring and comparing the area of shapes, using an array of paper tiles or mosaic squares, including part units to fill gaps at the edge of the shapes; comparing the total areas by combining the fractional parts to make whole units
• • Elaboration demonstrating how to use one unit repeatedly to measure the area of a shape; for example, using one paper square to measure and compare the area of a rectangle and a triangle; recording and explaining how they used part units to give a more accurate measure, and why they needed to ensure there were no gaps or overlaps
• • Elaboration investigating the ways First Nations Ranger Groups and other groups measure areas of land to make decisions about fire burns to care for Country/Place