A collection of interesting topics and ideas to fill spare moments...or perfect warm-up activities. 45 topics and mathematical ideas for the classroom or home, which are quick to introduce and set up but also genuinely stimulating and enriching. Although primarily designed to fill spare moments in normal lessons in Middle or High School, they enliven clubs, quizzes and end of term activities. They are an ideal source of thought-provoking investigations for those who need stimulating puzzles and explorations. Complete with answers and lots of follow-on material.