Maths - On a roll with rotations
Where you come in
Each week Craig Barton, creator of www.mrbartonmaths.com, picks a TES maths resource that has caught his eye and records a short video about it. After you have watched the video and used the resource in a lesson, we would love to hear from you. You can record your thoughts in the Comments section on the web page.
What is it?
This resource from atitterton has been created using Geometer's Sketchpad. It provides a simple but effective way to show how to rotate objects around a given centre of rotation on plain paper. Students can print out a screen-shot so that they can practise the rotation themselves with good old-fashioned pencils and paper. The teacher can then carefully illustrate to students how the rotation works on the interactive whiteboard.
Why I like it
Transformations - and rotations in particular - can cause students problems, and with a large class it is simply not practical to try to demonstrate the technique yourself using tracing paper at the front of the room. Likewise, you don't want to be getting into a tangle with co- ordinates and degrees of rotation until students have mastered the basics of where to put the pencil and tracing paper. This resource solves both these problems, offering a clear, simple visual demonstration.
What comes next?
The dynamic nature of the resource means it lends itself perfectly to extension questions, such as, "What happens to the image if I move the centre of rotation down?" and "What happens if the centre of rotation lies inside the object?" The original shape can also be manipulated as the rotation is taking place. Once these basics have been mastered, you can turn to something like Autograph for a more in-depth look at the topic of rotations.