Summary Collect leaves and rocks and arrange them into a repeating pattern. Use chalk to write out number patterns. Science content Math: Patterning Lessons activity is in Patterns in the playground or park Materials leaves, rocks and other collected items from the school grounds sidewalk chalk Procedure Students find leaves, rocks and other natural/manmade items from the school grounds. Use a flat area or picnic tables for students to arrange their items into repeating patterns. Students in small groups use sidewalk chalk to create a number pattern. The rest of the class guesses the next numbers in the pattern. Grades taught Gr 2 Gr 3