What behavior demonstrates a child's understanding of number sense?

The understanding of number sense involves a child's ability to comprehend various concepts related to numbers, including comparisons between them. Recognizing that the number 5 is greater than the number 3 reflects an awareness of numerical value and magnitude, which is essential for developing mathematical reasoning and problem-solving skills. This ability indicates that the child not only can identify numbers but also understands their relationships in terms of quantity, laying a strong foundation for future mathematical learning.

The other options, while related to mathematics, focus on different aspects. Recognizing shapes and colors pertains to geometry and visual recognition rather than number concepts. Counting to 20 demonstrates basic counting skills, which is a crucial part of number sense but doesn't necessarily show an understanding of how numbers compare to one another. Writing numbers neatly relates more to fine motor skills and presentation rather than the conceptual understanding of numbers.