By relating the sizes of the different planets to familiar objects, this activity helps to reinforce the relative sizes of the planets. Explain to the students that Uranus is slightly larger than Neptune is. If the grapefruit is larger than the softball, switch the labels. Ask the students to arrange the planets in order of increasing size. General Scientists use models everyday.
Models can be conceptual, mathematical, and scale.
Scale models are a concept with which students are already familiar in the context of model toys, maps, and globes. Scale models allow students to explore systems with scales from the microscopic to the astronomical that are beyond the realm of normal human experience. Mathematics Scale models utilize fractions, decimals, ratios, and proportions. Scale models allow students to make a connection between physical objects and mathematical concepts. Scale models provide a concrete, hands-on, method of exploring the nature of our solar system in a classroom setting.