More effectively than any other number sense framework, theirstransforms Greeno’s (1991) metaphor of environments for conceptual domainsto measureable form. The adaptability permitted by the interaction of these29three components in terms of content and developmental stages is both adetriment and an advantage. While its flexibility limits articulation of thenumber sense construct, it also allows for a fluid framework over time thatincorporates metacognition, growth, and context.