Abstract A common context for instruction in early algebra involves time, an invisible and intangible quantity commonly represented as intervals of length. This paper presents a case study of syntactically guided reasoning with the structure of an analogue clock involving a second-grade student. As her descriptions shifted from clock-reading procedures to a treatment of interval, she integrated conflicting ideas related to learned procedures for clock reading with time as experienced in the world. I discuss implications for early algebra related to strands for functions and quantitative reasoning.

中文翻译：

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隐形量：早期代数中的时间间隔/隐形量：早期代数中的时间间隔

摘要早期代数中常见的教学环境涉及时间，时间是一种不可见和无形的量，通常表示为长度间隔。本文介绍了一个句法指导推理的案例研究，它涉及一个涉及二年级学生的模拟时钟的结构。随着她的描述从时钟读取程序转变为间隔处理，她整合了与学习时钟程序相关的相互矛盾的思想，随着时间的流逝，世界上经验丰富。我讨论了与功能和定量推理相关的早期代数的含义。