LibGuides: Grades 3-4 How the World Works (HTWW): How the World Works (year A)

Idea and Inquiry

Central Idea: Our planet has formed over time and is still changing.

Lines of Inquiry:

1. The different materials that make up the Earth and its structures (geology)

2. The interactions among the Earth’s systems (systems)

3. The ways the Earth is changing (transformation)

Earth's Four Spheres

Four major parts of Earth work together as a complex system: rocks, water, air, and life. On a global scale, each part can be thought of as a sphere, roughly the same size and shape as the planet. The four parts are called the geosphere, hydrosphere, atmosphere, and biosphere.

Videos about the Earth

undefined Could I Dig a Hole Through the Earth?

Have you tried to dig a deep hole? So deep that you could dig all the way to the other side of the Earth? It’s pretty hard, and lots of people have tried. So what’s stopping us from digging through the Earth? It has something to do with layers and a lot of heat!

Layers of the Earth undefined

The Earth is approximately 4,000 miles from the center to its surface, but what makes up those miles of earth?

Learn about the four spheres of the Earth: geo-sphere (ground), hydro-sphere (water), atmo-sphere (air), and bio-sphere (life). Everything on the planet falls into one of these subsystems, which are interconnected to each other. Sabrina Cruz explains these four spheres in two animated videos. Think of geosphere as the foundation for the other three spheres, which exist atop it. The biosphere includes all living things - plants and animals living in different biomes. The hydrosphere includes all of the water (fresh, salt, underground, frozen) on the planet. The atmosphere includes all of the layers of gases that surround the planet.

undefined Geosphere, Biosphere, Hydrosphere, Atmosphere - a rap!

The Earth is a mighty big place y’all.

All kinds of things in and on and around

They have names too

Let me tell you how the 4 spheres of the Earth get down

Geosphere, biosphere, hydrosphere, atmosphere

It’s mouth full but let me be clear…er

....

What On Earth: Crash Course Kids #10.1

How do the different spheres interact with each other? In this episode of Crash Course Kids, Sabrina chats with us about how two of the spheres do, in fact, work together.

Interactions of the Earth's Spheres

"...You'd have a difficult time finding an example where one sphere doesn't either touch or interact with at least one other. This is important because these interactions are what drive Earth's processes."

undefined Weathering And Erosion

In this episode of Crash Course Kids, Sabrina gives us a real world example of how the Hydrosphere and Geosphere affect each other in the form of Weathering and Erosion. Think of Weathering as the force that makes a mess and Erosion as the force that cleans it up.

Landforms, Hey!

In this episode, Sabrina chats about how things like mountains, volcanoes, and plateaus come into being.

A Change of Scenery undefined

"The world changes. It really does! But sometimes it changes so slowly that we don't notice it. Other times it changes REALLY FAST!!! In this episode of Crash Course Kids, Sabrina talks about some of the reasons things can change quickly or slowly. "