Pack of 10 ‘A4 Tell The Time Dry Erase Boards’ with 1 x ‘A3 Teacher Dry Erase Board’: These uniquely designed dry erase boards are brilliant to calculate elapsed time when using Nexus Elapsed Time 24 Hour Rulers. Pack of 10 ‘Folding Elapsed Time 24-hour Rulers’: Folding Elapsed Time Ruler helps students understand and visualize the very difficult concept of elapsed time. Made of high impact plastic, with easy to read 24-hour graphics, and comes packed in a Gratnells tray with a lid.