Numbers can be written in different forms, depending on how they are being used. How fractions or decimals based on measured quantities should be written depends on how precise the measurements are and how precise an answer is needed. Mathematical statements can be used to describe how one quantity changes when another changes. Rates of change can be computed from differences in magnitudes and vice versa. Graphs can show a variety of possible relationships between two variables.
Students observe and record the temperature changes of different materials in both sun and shade.
Students then graph their results for each material on a single graph to show the similarities and differences between the materials in sun and shade environments. Shapes can match exactly or have the same shape in different sizes. Lines can be parallel, perpendicular, or oblique. Shapes on a sphere like the earth cannot be depicted on a flat surface without some distortion. The graphic display of numbers may help to show patterns, such as trends, varying rates of change, gaps, or clusters.