**Task Name : **Circle Investigation |
**Task Level : **I (Year 8) |

**Semester : **1 |
**Topic :** Factors and Multiples |
**VC Strand : **Real Numbers; Units of Measurement |

**Web Address : **http://maths.crusoecollege.vic.edu.au/rnI |

**Equipment Needed : **String, tape measures for measuring circumference; rulers for measuring diameter. |

**Victorian Curriculum outcome : **Investigate the concept of irrational numbers, including π. Investigate the relationship between features of circles such as circumference, area, radius and diameter. Use formulas to solve problems involving circumference and area. |

**Task description : **Students find ten circular objects around the learning space and record the diameter and circumference of each. They then find the ratio of circumference to diameter of each circle. This will enable them to see that the ratio is always π. They then use this to find unknown radii, diameters and circumferences of circles. |

**Assessment options : **Photograph of circular objects. Students may type or write their final tables and add to their blog post. |

**Teacher notes : **Students need to measure as accurately as possible for this to work. Encourage them to be as precise as possible, and to measure circles of varying size, particularly larger ones, to reduce error. |