In this article, the author clarifies the distinction between numeracy and mathematics and the implications of this distinction for teachers of mathematics. In doing so she has, of necessity, focused on one--albeit significant--high stakes assessment genre used on Australian students that purports to measure numeracy. It is essential that teachers understand the genre used in the National Assessment Program Literacy and Numeracy (NAPLAN) numeracy test in order for their students to be prepared for it. There does, of course, need to be some balance in how to do this: spending inordinate amounts of time "preparing for the test" creates another set of problems. However, if the preparation is embedded in the mathematics program of the school, where students are taught and required to clarify contexts and situations, make choices about the mathematical models, tools and strategies needed, and to critique their own mathematics choices as well as those of others, teachers will not only be improving students' numeracy capability but also their mathematics skills and understandings. The NAPLAN numeracy test is not perfect. However, the author believes that the way in which the results are used is more problematic than the test itself. Teachers can learn a lot from the test results if they analyse the data generated to inform their teaching and learning programs; i.e., if they were to use the information provided by the test data as assessment "for" learning, rather than as assessment "of" learning. Finally, teachers must ensure that they are teaching their students for numeracy attainment: mathematics skills and procedures alone are insufficient for students to have the capabilities needed to be numerate at school, home, at work, in the community and in civic life, let alone to be successful on an assessment genre designed to assess numeracy in a pen and paper test.