Grade 3Science

Focus: This unit introduces Grade 3 students to fundamental concepts of habitats, adaptations, ecosystems, and environmental changes over time. Students will learn about the relationships between living things and their environments. They see that organisms are adapted to live in specific habitats. But when the habitats change, suddenly or over millions of years, the same adaptations that allowed success in one habitat may not be those that ensure survival in another.

Students understand important aspects of the relationship between the adaptations of living things and their environments by:

  • exploring concepts of traits and adaptations, including living in groups;
  • witnessing case examples of changes in ecosystems, ranging from beaver dam flooding to widespread human-caused disruptions; and
  • examining the fossil record to see that ecosystems in the past have changed and how the living thing in them have changed or species have gone extinct.

Students also learn that engineers use their knowledge of ecosystems to develop solutions and build things that respond to or prevent ecosystem damage. As a series of culminating activities, students explore the principles and practices of engineering design, such as scientifically defining a problem to be solved and evaluating and optimizing possible solutions.

Number of Lessons: 16

Lesson Time: 30–45 minutes daily. Each lesson may be divided into shorter segments.

Please note that certain lessons in this unit are designed for multiple days, resulting in approximately 23 days of instruction. For more information, please refer to the recommended Pacing Guide within the Teacher Guide.


Additional Search Terms:

habitat • plant • animal • organism • individual • population • survive • adaptation • ecosystem • environment • change • invasive species • climate • migrate • conservation • extinct • fossil • problem • solution • nonfiction • informational text


CKSci Grade Levels: CKSci units are correlated to topics at the grade levels specified in the K–5 Core Knowledge Science Sequence.

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