Science Fair Presentation

The science fair is your opportunity to share what you have investigated and learned throughout the year. A great science fair presentation explains the variable you changed in your investigation, uses scientific vocabulary, and invites your audience to ask questions. This lesson reviews all four Grade 3 Science units to prepare you.

Planet 1 — Living Things (L1–L8)

• Life cycles: plants go from seed to mature plant; animals go from egg or birth through growth stages.
• Food chains: producers are eaten by primary consumers, then secondary consumers.
• Habitats: every animal needs food, water, shelter, and space.
• Adaptations: features that help organisms survive in their environment.

Planet 2 — Earth and Space (L9–L16)

• Earth layers: crust, mantle, outer core, inner core.
• Rocks: igneous, sedimentary, metamorphic.
• Water cycle: evaporation, condensation, precipitation, collection.
• Moon phases: 8 phases in a 29.5-day cycle.
• Weather instruments: thermometer, rain gauge, wind vane, barometer.

Planet 3 — Matter and Energy (L17–L24)

• States of matter: solid, liquid, gas — can change with heating or cooling.
• Physical vs chemical changes: a physical change makes no new substance (many can be undone); a chemical change makes a new substance and usually cannot be undone.
• Circuits: battery, wire, bulb, switch; closed = on, open = off.
• Magnets: opposite poles attract; same poles repel; only iron, nickel, steel are magnetic.

Planet 4 — Human Body and Health (L25–L32)

• Body systems: skeletal, muscular, digestive, circulatory, respiratory, nervous.
• Nutrition: carbohydrates for energy, protein for growth, vitamins and minerals for protection.
• Healthy habits: regular exercise, enough sleep, good hygiene, balanced meals.
• Safety: follow safety rules indoors and outdoors.