Student need to be aware of how enlargements are done from a centre of enlargement using the ray method.

• Enlargements presentation PowerPoint;
• Enlargements presentation support sheet;
• Enlargements worksheet.

The website Waldomaths - www.waldomaths.com - has an excellent enlargement java in its 11-16 section.

Open the Enlargements presentation on the interactive whiteboard (IWB). Ask the students to try and visualise how the shapes will enlarge and what letter they will form. If you feel it is necessary, provide students with the Enlargements presentation support sheet to work on in pairs.

Go through the answers on board by clicking the mouse, this PowerPoint uses the ray method and the rays are drawn to double their original length. Emphasise that this is because the scale factor is 2 and it would be different with another scale factor.

The last slide shows the worksheet they will be working on and how one of the enlargements works. Switch on your IWB transparent sheet to write over the slide and do as many extra enlargements as you feel are necessary.

Hand out the Enlargements worksheet.

Students work on their worksheet. If done correctly all the shapes fit together to form the word SIZE. Keep an eye out for students who have made obvious mistakes. Do not let them colour in until they have finished it and you have checked it (the advantage of this is it takes only a moment to check they have done it correctly).

At the end of the lesson, tell students what the words should be. They can finish the worksheet for homework and colour it in should they wish to. These make nice display work but don’t put them up until you have done them with all your classes otherwise they will be far too tempted to copy.