Robbie Case's Theory That Children Acquire a Central Conceptual Structure

Multiple Choice

Robbie Case's theory that children acquire a central conceptual structure for numbers can best help you explain which one of the following?

A) Why 6-month-old Frederika is surprised when an experimenter shows her a display of three objects, covers the display and seemingly removes an object, and then reveals that the display still has three objects
B) Why 8-year-old Eldon cannot answer the question, "Which is more, the difference between 2 and 6 or the difference between 7 and 9?"
C) Why 12-year-old Heidi has difficulty understanding percentages
D) Why 16-year-old Garrett has difficulty with proofs in his geometry class