Since 2000 gender differences in mathematics achievement in Australia have reappeared. In this paper we report on the achievement outcomes of girls and boys in a longitudinal study of reform in low economic scho ol communities. Analysis of st udent data to inform teaching was one element of student centred approaches implemented by teachers. Teachers targeted students’ next point of learning and more girls than boys participated in mathematics intervention programs. Growth in achievement was greater for boys than for girls in the primary years, and so the achiev ement gap that favours males widened. It is concluded that student centred approaches need to be gender inclusive. ------Mathematics : traditions and (new) practices : proceedings of the AAMT-MERGA conference held in Alice Springs, 3-7 July 2011, incorporating the 23rd Biennial Conference of The Australian Association of Mathematics Teachers Inc. and the 34th Annual Conference of the Mathematics Education Research Group of Australasia Inc.