Our audio CDs offer students tips and practice for working calculations in their heads instead of on paper.  Some recorded exercises involve only numbers and mathematical operations.  Others are "word problems" for students to analyze, then calculate.   Narrative problems are drawn from situations students are likely to encounter in everyday life.  Some exercises allow note-taking; others require that students complete calculations in their heads.   In this audio format, students' math abilities are not tied to their reading abilities, but their listening skills get a good workout.  The format is similar for all three packages, with problems increasing in difficulty.