Exploring the individual differences of the longitudinal growth of early numeracy (EN) in young children with Intellectual disabilities (IDs) prerequires the critical stage of exploring and validating the potential factor structure. Despite the fact that Relational Skills (RS), Counting Skills (CS) and Operations (O) are expected to constitute distinct domains of EN, there is not sufficient evidence to support either the above position or the position that they are different means of assessing a general-informal numeracy skill construct. This study was designed to shed light in the field through the evaluation of a measurement model describing the structure of RS, CS and O domains of EN and their interrelation. The sample included N = 155 children with IDs, enrolled in special school classes, mentally aged between 5;02 (y;m) and 6;10 (M = 5.11, SD = 0.974). Confirmatory Factor Analysis indicated a “good fit” of the two-factor model (RS, CS + O) of EN in ID (RMSEA=.029 < 0.08, CFI = 0.98 ≥ 0.90 and SRMR = 0.000 < 0.08). No measurement invariance across gender was reported for the proposed two-factor model of EN. The nested EN models validated full measurement invariance across gender. Finally, educational implications are discussed.

探索智力障碍幼儿早期算术（EN）纵向发展的个体差异，需要探索和验证潜在因素结构的关键阶段。尽管关系技能 (RS)、计数技能 (CS) 和操作技能 (O) 预计将构成 EN 的不同领域，但没有足够的证据支持上述立场或它们是不同评估手段的立场一般非正式的计算技能构造。本研究旨在通过评估描述 EN 的 RS、CS 和 O 域结构及其相互关系的测量模型来阐明该领域。样本包括N = 155就读于特殊学校班级、心理年龄在5;02 (y;m)至6;10 之间（M = 5.11，SD = 0.974）的具有 ID 的儿童。验证性因素分析表明，ID 中 EN 的双因素模型（RS、CS + O）“拟合良好” （RMSEA=.029 < 0.08，CFI = 0.98 ≥ 0.90 和 SRMR = 0.000 < 0.08）。对于所提出的 EN 双因素模型，没有报告跨性别的测量不变性。嵌套 EN 模型验证了跨性别的完整测量不变性。最后，讨论了教育意义。