A child puts away toys and learns that the quantity remains the same regardless of the order in which they are put away. Which concept is the child learning?

• A. One-to-one correspondence
• B. Subitizing
• C. Number conservation
• D. Affix

Answer: (C)

The main idea here is conservation of number: the quantity stays the same even when the arrangement changes. When the child puts away toys in a different order, they’re learning that counting reflects how many items there are, not how they’re arranged. This shows an understanding that number is invariant to perceptual changes like order or layout, a step in kids moving from focusing on appearance to grasping true quantity.

This isn’t about matching each item to a count (one-to-one correspondence), which is more about linking objects to numbers as you count. It isn’t about instantly recognizing a small number of items without counting (subitizing). And it isn’t related to an unrelated term like affix.