This is the fourth strand in a brand new series of Developing Mathematics, developed to be fully in line with the government's Revised Primary Framework for Mathematics. It features completely new content, a fresh up-to-date look both inside & out, & comes with a CD-ROM that contains all of the activity sheets in a customisable format. Using our unique software supplied on the CD-ROM, teachers can effortlessly adapt the activities to make them more challenging or to create further exercises for children who need a bit more practice. New text & images can be easily imported & saved without fear of corrupting the original files, & teachers can print out as many copies as they wish.