The authors contest a politician's claim that the National Numeracy Strategy (NNS) in English primary schools has been an undisputed success with no contribution from educational researchers. First, the key role of researchers and research in the development of the NNS is outlined. Then there is a description of the Leverhulme Numeracy Research Programme, a linked set of research studies combining a large-scale longitudinal survey and qualitative case studies. Results suggest that the NNS had a positive but small effect on numeracy standards, but that there are many schools, children and areas of mathematics for whom the effect has been negligible or negative. The discussion of reasons for this relates to evidence from the Leverhulme Programme and elsewhere about the effects of different factors on attainment. Finally, there is some question of whether government and government agencies are being completely open about the evidence of effectiveness of the NNS. (Contains 9 tables.)