This paper describes a "hands-on task" called Number Tiles, which is Task 43 in the collection constructed for the Mathematics Task Centre Project, and available at www.blackdouglas.com.au or www.curriculum.edu.au. This task is rich in possibilities and directions. It should be used as a planned curriculum experience at several year levels to achieve the most from it. A wide range of students can try this problem, and then exit from it at different points feeling that they have gained some success in finding some of the solutions.