Seven-year-olds who had difficulty understanding 1st-grade work received one of two forms of small-group instruction. Half of the children were randomly assigned to receive four months of instruction in recognizing, comprehending, and reproducing both logical and arbitrary patterns (sequences) involving numbers, letters, shapes, colors, orientations, causes and effects, and temporal events. The other children received yoked instruction in the academic subject matter their teachers thought most useful. At the end of the school year, the patterning group significantly outperformed the control group on measures of patterning and academic achievement. This is empirical evidence showing that a broad understanding of the many different possibilities for pattern rules is an important thinking ability that facilitates academic achievement for 1st-graders. (Contains 2 tables.)