“Flow Sums, Student Workbook ” contains a suite of thirty arithmetical challenges. In each “Flow Sum”, the student is provided with a gateway number and they have to work their way through the maze of arrows, following the directions and instructions that are provided along the way, to discover the missing answer at the end of the maze. These number challenges can be planned and implemented to incorporate a combination of mental activity and written activity. Alternatively, the challenges can be organised as activities involving the use of a calculator.