Children have been using numbers since infancy in their daily life. Numerical representations have been studied before in the way of basis of number processing in infancy and higher number processing in childhood such as addition. However, it has been left unsolved that the relationship between development of numerical representations and other number concept.
In this study, I first studied development of numerical representations in infancy (4 and 5 years) by use of O-to-100 number line. As a result, between 4 years and 5 years children, the pattern of estimates progressed from logarithmic to linear representations. This result also indicated that the developmental transformation was seen earlier than previous researches.
Second, I also studied that the relationship between development of numerical representations and other number concept. Here, along with the number concept which was involved with numerical representations in previous researches, I evaluated the possible association of understanding of three number concepts (ordinal, cardinal and number conservation) as a precondition to understanding of number. Then, the development of numerical representations has a correlation with counting, cardinal number and number conservation. The reason which this study could get the result was probably that small number of correct answers in the other group which didn’t fall into logarithmic or linear representations. Thus, it was indicated that there are one of the number concepts supporting the developmental transformation the other group from to logarithmic or linear representations.