Proportional reasoning is one part of mathematics that is particularly hard to apprehend for children. At the same time, research suggests that already at an early age children develop an ability to make sense of some proportional situations. Previous research has shown that language – be it language in general or language related to mathematics – plays a crucial role in mathematical thinking and learning. The domain of proportional reasoning involves highly content-specific vocabulary (e.g., double). Individual differences in children’s general vocabulary or specific mathematical vocabulary might explain differences in children’s proportional reasoning abilities. However, to our knowledge, no studies investigated the role of language in proportional reasoning at an early age. The present study (n = 343) aims to address this gap by longitudinally investigating if specific mathematical vocabulary related to proportional reasoning in the first year of elementary school predicts proportional reasoning abilities in the second year of elementary school, over and above general vocabulary. Results showed that there were large individual differences between children’s specific mathematical vocabulary knowledge related to proportional reasoning. Furthermore, a hierarchical linear regression analysis showed that some specific mathematical vocabulary concepts related to early proportional reasoning in the first year of elementary school were a unique predictor for proportional reasoning abilities in the second year of elementary school over and above age, SES and general vocabulary. Theoretical and methodological implications are discussed.

比例推理是数学的一部分，对于孩子而言，它尤其难以理解。同时，研究表明，儿童从小就已经具备理解某些比例情况的能力。先前的研究表明，语言（无论是通用语言还是与数学有关的语言）在数学思维和学习中都起着至关重要的作用。比例推理领域涉及特定于内容的高度词汇（例如double）。儿童一般词汇或特定数学词汇的个体差异可能解释了儿童比例推理能力的差异。然而，据我们所知，尚无研究在早期就研究语言在比例推理中的作用。本研究中（Ñ= 343）旨在通过纵向调查与小学一年级比例推理相关的特定数学词汇是否能够预测小学二年级以上普通词汇的比例推理能力，从而弥补这一差距。结果表明，与比例推理相关的儿童特定数学词汇知识之间存在很大的个体差异。此外，分层线性回归分析显示，与小学一年级早期比例推理有关的某些特定数学词汇概念是小学二年级以上年龄，SES和普通词汇中比例推理能力的独特预测因子。讨论了理论和方法论的含义。