Mathematics Recovery was the outcome of a three-year research and development project at Southern Cross University, conducted in 1992-5. The project received major funding from the Australian Research Council and major contributions in the form of teacher time, from regional government and Catholic school systems. Over the 3-year period, the project involved working in 18 schools with 20 teachers and approximately 200 participating first-grade students. MR can be regarded as consisting of two distinct but interrelated components. One component concerns an elaborated body of theory and practice for working with students, that is, teaching early number knowledge. The second component concerns distinctive ways of working with teachers, that is, providing effective, long-term professional development in order to enable teachers to learn about working with students. MR has as its basic orientation von Glasersfeld's theory of cognitive constructivism. One of the key elements of the MR program is its framework for assessment and learning - usually referred to as the Learning Framework in Number (LFIN). The LFIN is regarded as a rich description of the students' early number knowledge. This includes, but is not limited to, the strategies that student uses to solve what adults might regard as simple number tasks (additive, subtractive). Recent research highlights the relative complexities of students' early number knowledge, and the usefulness of close observation and assessment in enabling detailed understanding of students' arithmetical knowledge and strategies. Critical to the efforts of teachers to address students' learning difficulties in mathematics are elaborated exemplars of theory-based practice directed at addressing mathematics learning difficulties. [Author abstract, ed]