Thinking About Numbers is a text designed for 11-12-year-olds in the first year of the programme. It explores mathematical concepts such as accuracy, one-to-one correspondence, sets, negative and irrational numbers as well as efficiency, justice, technology and time. It supports the capability of making numerical statements about the reality, as well as the capability to think about the social dimension of such statements. The story follows the conversation of a group of classmates and their teacher, living in a rural village in the Philippines.