This paper explores the Counting development of Australian children participating in the Early Numeracy Research Project (ENRP) who were identified as low-attaining using an individually administered assessment interview and a research informed framework of growth-points. The progress of Grade 1 and Grade 2 children who participated in an intervention program was compared to children who did not. Results suggest that the intervention was more effective for Grade 1 children, but that the effectiveness of the intervention seemed to depend on the growth point transitions children needed to make. (Contains 1 figure and 6 tables.) [The ENRP was supported by grants from the Victorian Department of Education, Employment and Training, the Catholic Education Office (Melbourne), and the Association of Independent Schools Victoria. For complete proceedings, see ED500859.]