The Maths Trails teacher books and CD-ROMs introduce, develop and enhance mathematical problem-solving skills. 'Visualising' is part of a series of mathematics enrichment titles developed by the NRICH team at Cambridge University. This Teacher's Guide details 17 problem-solving activities arranged in a trail, each one developing the skill of visualising. Full supporting notes for teachers include useful questions, prompts and hints for students and possible outcomes for each activity, as well as ideas for 16 further visualisations. The accompanying CD-ROM contains animations and interactivities to help introduce and support the activities. Links to similar problems on the NRICH website are given and students are encouraged to post their solutions on the site.