This centers-based lesson on prime and composite numbers is designed for two-days of 45-minute lessons or one-day of a 90-minute lesson block. The lesson provides differentiated instruction using the H.O.P. Centers Framework. H.O.P. stands for Hands-On, Open-Ended, and Practice which are the themes for each of the three centers in the framework. Lesson structure is designed using brain research principles. In this lesson students will learn how to identify/define prime and composite numbers with a short engaging lesson, hands-on activity using Eratosthenes Sieve, practiced writing about a word problem using prime and composite numbers, and engage in tiered practice of the concept.