Activity Six: 
Concept Application: Scale Models to Planet Size 
Grade Level Content: 3-6
Processes: Observing, Communicating,  
Comparing, Relating, Inferring
Developmental Stages: Sensory Motor, Pre-Conceptual, Intuitive,  
Concrete-Operational, Formal Operational
Review the spheres chosen to represent the relative size of the planets from the worksheet in Activity Four. 

Start the discussion with the following question: 
What do we know about the size of the Earth compared to the other planets?  
Compare sizes of planets with known objects such as: 

  • basketball
  • volleyball
  • soccer ball
  • baseball
  • ping pong ball
  • golf ball
  • marble
  • pea
Discuss how these could be scale models of the planets. 

Using the sizes represented by these spheres, students will build models of the planets by blowing up balloons, using paper mache, clay ,etc. 

Students will display their scale models of the planets and share with the class how they chose the scale.