Three-year-old May nests cups; she places the smallest into the largest and then struggles with a medium into the smaller cup. This type of play would most likely build a foundation for May's understanding of which mathematical concept?

Three-year-old May nests cups; she places the smallest into the largest and then struggles with a medium into the smaller cup. This type of play would most likely build a foundation for May's understanding of which mathematical concept?

• A. counting
• B. seriation
• C. equivalence
• D. matching

Answer: (B)

The idea being explored is seriation—the ability to order objects along a dimension, such as size. In May’s play with nesting cups, she’s actively comparing sizes and arranging them in a sequence: the smallest cup fits into the largest one, showing she recognizes a size order. When she tries to fit the medium into the smaller cup, she’s testing the boundaries of that ordered sequence and refining her understanding of which sizes go before or after others. This kind of hands-on sorting and ordering lays the groundwork for recognizing and predicting size relationships, a foundational skill for more complex mathematical thinking. Counting would involve naming quantities, which isn’t what she’s doing here. Equivalence would involve noticing sameness in size or amount, which isn’t the focus. Matching would involve pairing items that go together or share a attribute, rather than placing them in an ordered sequence by size.

The idea being explored is seriation—the ability to order objects along a dimension, such as size. In May’s play with nesting cups, she’s actively comparing sizes and arranging them in a sequence: the smallest cup fits into the largest one, showing she recognizes a size order. When she tries to fit the medium into the smaller cup, she’s testing the boundaries of that ordered sequence and refining her understanding of which sizes go before or after others. This kind of hands-on sorting and ordering lays the groundwork for recognizing and predicting size relationships, a foundational skill for more complex mathematical thinking.

Counting would involve naming quantities, which isn’t what she’s doing here. Equivalence would involve noticing sameness in size or amount, which isn’t the focus. Matching would involve pairing items that go together or share a attribute, rather than placing them in an ordered sequence by size.