This report investigates how practitioners use calculators with adult learners to develop their numeracy skills. Pocket electronic calculators, including those on mobile phones, are a readily-available, cheap, practical resource with the potential to help learners develop a feel for number. However, research (Coben et al. 2007) has shown that calculators are barely used in adult numeracy classes. Many teachers said they did not use calculators in the classroom because they felt pressured by the format of the national numeracy tests at Levels 1 and 2. They felt that because learners were not allowed to use calculators in the tests, it was more relevant to develop ‘pen and paper’ calculation skills and to ensure that learners were familiar with written algorithms. Learners also have mixed feelings about calculators. However, if calculators are used imaginatively as part of an integrated teaching and learning strategy that includes developing estimation and problem-solving skills, they provide adult learners with valuable opportunities for self-directed and self-paced learning using realistic learning.