Summary: The development of patterning strategies during the year prior to formal schooling was studied in 53 children from 2 similar preschools. One preschool implemented a 6-month intervention focusing on repeating and spatial patterns. Children from the intervention group demonstrated greater understanding of unit of repeat and spatial structuring, and most were also able to extend and explain growing patterns 1 year later. The findings indicate a fundamental link between patterning and multiplicative reasoning through the development of composite units. (Contains 8 tables, 5 footnotes, and 10 figures.) (ERIC)