The purpose of this longitudinal study is to investigate whether an early childhood intervention using an explicit and transparent number naming system will have a lasting benefit to English and Spanish speaking children in their mathematics achievement related to number sense by accelerating their acquisition of concepts of numeracy and place value recognition. Statistical analysis of the results of the "Stanford Achievement Test" administered to school children in grades 1 through 5 at a school in Texas (USA) over a 6-year period of time showed consistent differences between those children who had participated in the intervention program by learning to count using explicit numbers names in Pre-Kindergarten and those who had not participated in the program. The advantages of this study were most apparent in children in the fourth grade, 6 years after their Pre-Kindergarten experience with explicit number names, particularly with those who had 2 years of experience with explicit number names.