Graphical display of numbers may make it possible to spot patterns that are not otherwise obvious, such as comparative size and trends. Many objects can be described in terms of simple plane figures and solids. Shapes can be compared in terms of concepts, such as parallel and perpendicular, congruence and similarity, and symmetry. Symmetry can be found by reflection, turns, or slides. Areas of irregular shapes can be found by dividing them into squares and triangles.
Scale drawings show shapes and compare locations of things very different in size.
From the model, students use an overlay grid to transfer the locations of various objects in the model to a paper grid. Students are then given the task to create a paper model of their school area, using the information they obtained from their overlay grid. Summary predictions are usually more accurate for large collections of events than for just a few. Even very unlikely events may occur fairly often in very large populations. Spreading data out on a number line helps to see what the extremes are, where they pile up, and where the gaps are.