This is a splendid collection of 45 topics and mathematical ideas for the classroom which are quick to introduce and set up but also genuinely stimulating and enriching. Although primarily intended to fill spare moments in normal lessons, they would also be fine for maths clubs and end of term activities. In addition they could provide a source of thought-provoking investigations for children who need some extra work while the rest of the class finishes an earlier assignment. Complete with answers and lots of follow-on material.