This article describes how in early mathematics learning, young children are often asked to recognize and describe visual patterns in their environment--perhaps on their clothing, a toy, or the carpet; around a picture frame; or in the playground equipment. Exploring patterns in the early years is seen as an important introduction to algebraic thinking as children begin to notice similarities and differences between and among patterns, create rules to describe relationships, and eventually represent those relationships using symbols. Although young children are readily able to recognize patterns in their environment, they may not be attending to features that allow them to describe the patterns they see in "mathematically useful" ways. The author concludes that curricular expectations for preschool and kindergarten children to recognize, duplicate, and extend primarily sequential patterns may indeed contribute to algebraic reasoning, but only if they learn to see the mathematical properties and describe the repeating structures in mathematically predictable ways.