Ratio & proportion
This activity includes a Geometer’s Sketchpad file and an accompanying worksheet which gives pupils a structured start to an investigation which can open up as the work progresses. However, teachers could present the investigation in a much more open-ended way by providing pupils with the GSP file alone. The activity is designed for pupils who are interested in developing their ICT skills through using dynamic geometry software, and there are step by step instructions provided allowing pupils to construct their own dynamic drawing.

Year 8 objectives covered:
• Use the unitary method to solve problems involving ratio and direct proportion
• Enlarge 2-D shapes given a centre of enlargement and a positive integer scale factor
• Explore enlargement using ICT
Year 9 objectives:
• Use proportional reasoning to solve problems
• Explore similarity
Year 10 objectives:
• Know that if two 2-D shapes are similar then corresponding sides are in the same ratio
This resource gives pupils the opportunity to explore the relationship between ratio and enlargement and links concepts of similarity, scale factors and proportionality.