This lesson plan involves preschool students counting dots on a worm template from 0 to 20. The teacher will introduce the activity by discussing worms. Students will then count out and place at least 20 dots on their worm template. The teacher will monitor students and have them count out loud to check their work. An assessment sheet will track if students can correctly count sequences to 10 and 20. The goal is to practice number sense and counting skills up to 20.