Cogwins publishes mathematics materials for secondary classrooms. New elements are introduced one at a time, each with a worked example before it is combined with anything else. Related questions are closely matched: one element changes while the rest stays the same. Each pack is written to be taught straight through, while families of sheets can also be selected, skipped or reordered to suit the class. Resources combine printable Student and Teacher materials with matching teacher-led PowerPoint decks. Clear mathematics, careful sequencing and practical classroom flexibility.