Two recent books on development statistics address what seem to be polar ends of the spectrum of number generation. Morten Jerven’s “Poor Numbers: How we are misled by African development statistics and what to do about it” raises extremely important issues about official data sets that are usually taken for granted as representing the real facts about development. Jeremy Holland’s “Who Counts? The power of participatory statistics” continues to make the case for the validity, usefulness and intrinsically empowering impact of data collected with and for the communities whom development is supposed to affect while charting progress on the challenges of scaling up these approaches. Seen together they frame some core issues of knowledge and power which lie at the heart of development: the questions of who needs numbers and how they are produced and used.