Studies of one-to-one programs consistently report lower use of laptops in mathematics classrooms compared to other subjects but do not elaborate reasons for these observations. This mixed-method study investigated the experiences and beliefs of 28 mathematics teachers at five secondary schools during the second year of the New South Wales Digital Education Revolution laptop program. While some mathematics teachers planned for students to use their laptops up to once a week, most reported less frequent use in the classroom. Teachers were grouped into categories "Non Adopters," "Cautious Adopters," and "Early Adopters" according to reported classroom use of laptops, then analysed for differences in confidence, knowledge, and beliefs relating to technology for teaching and learning mathematics. A prevalent belief limiting laptop use is that students authentically learn mathematics only using pen and paper. Cautious Adopters and Non Adopters expressed beliefs that laptops exacerbate classroom management problems, especially for lower-achieving students. In the context of ability-streamed classes these beliefs effectively ruled out use of laptops for entire classrooms.