# YEAR ONE MATHS FOCUS

## MEASUREMENT AND GEOMETRY

Area

Learning Experiences

Area

## AREA

OUTCOME

A student:

MA1-10MG: measures, records, compares and estimates areas using uniform informal units

Teaching Points | In Stage 1, measuring the areas of objects using informal units enables students to develop some key understandings of measurement. These include repeatedly placing units so that there are no gaps or overlaps and understanding that the units must be equal in size. Covering surfaces with a range of informal units should assist students in understanding that some units tessellate and are therefore more suitable for measuring area. |

When students understand why tessellating units are important, they should be encouraged to make, draw and describe the spatial structure (grid). Students should develop procedures for counting tile or grid units so that no units are missed or counted twice. | |

Students should also be encouraged to identify and use efficient strategies for counting, eg using repeated addition, rhythmic counting or skip counting. | |

It is important that students have had some measurement experiences before being asked to estimate areas, and that a variety of estimation strategies is taught. |

Language | Students should be able to communicate using the following language: area, surface, measure, row, column, gap, overlap, parts of (units), estimate. |

## EXPECTATIONS OF ATTAINMENT

Measure and compare areas using uniform informal units | compare, indirectly, the areas of two surfaces that cannot be moved or superimposed, eg by cutting paper to cover one surface and superimposing the paper over the second surface |

predict the larger of the areas of two surfaces of the same general shape and compare these areas by cutting and covering | |

use uniform informal units to measure area by covering the surface in rows or columns without gaps or overlaps | |

– select and use appropriate uniform informal units to measure area (Reasoning) | |

– explain the relationship between the size of a unit and the number of units needed to measure an area, eg ‘I need more tiles than workbooks to measure the area of my desktop’ (Communicating, Reasoning) | |

– describe why the area remains constant when units are rearranged (Communicating, Reasoning) | |

– describe any parts of units left over when counting uniform informal units to measure area (Communicating) | |

– use computer software to create a shape and use a simple graphic as a uniform informal unit to measure its area (Communicating) | |

record areas by referring to the number and type of uniform informal unit used, eg ‘The area of this surface is 20 tiles’ | |

estimate areas by referring to the number and type of uniform informal unit used and check by measuring | |

– discuss strategies used to estimate area, eg visualising the repeated unit (Communicating, Problem Solving) |

Learning Experiences

To be added