Educational worksheet about the ocean, highlighting facts and key details for learning.

Let’s go step by step to solve this task.

We are given a short text about the ocean, and we need to:
1. Underline or highlight the main idea of the text.
2. Complete three sentences at the bottom using key details from the text.
3. Fill in “The topic of the text is” and “The main idea of the text is”.

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First, let’s read the text carefully:

> The ocean is important to all living things. More than 70 percent of Earth’s surface is covered by water. If you give Earth more water space, it would look similar to a blue marble. The Pacific Ocean is the largest ocean on Earth (largest habitat). There is only one world ocean and just like the air moves around us, water flows between the oceans. Just like the air moves around us, different animals live in different parts of the ocean depending on what they need to stay alive. One way to help the ocean is to keep healthy for years to come. The ocean is important to all living things. Over half of the Earth’s surface is covered with saltwater. Scientists have only explored part of them. There is still so much left to explore!

Wait — there’s a small error in the original text:
It says “One way to help the ocean is to keep healthy for years to come.” That doesn’t make sense as written. It probably meant:
→ “One way to help the ocean is to keep it healthy for years to come.”
But since we’re working with what’s given, we’ll use the meaning that makes sense: keeping the ocean healthy.

Also note: The first sentence and the second-to-last sentence both say:
“The ocean is important to all living things.” → This is likely the main idea.

Now, let’s find the topic of the text.

Topic = What the whole text is about → It’s clearly about the ocean.

Main idea = The most important point the author wants you to remember → Repeated twice: “The ocean is important to all living things.”

So:

→ The topic of the text is: the ocean

→ The main idea of the text is: The ocean is important to all living things.

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Now, let’s pick 3 key details from the text to fill in Key Detail #1, #2, and #3.

Key details are facts that support the main idea.

From the text:

- More than 70% of Earth’s surface is covered by water.
- The Pacific Ocean is the largest ocean on Earth.
- There is only one world ocean; water flows between oceans.
- Different animals live in different parts of the ocean based on their needs.
- Over half of Earth’s surface is covered with saltwater. *(Note: This repeats the 70% fact but specifies “saltwater”)*
- Scientists have only explored part of the ocean — there’s still much to explore.
- We can help the ocean by keeping it healthy.

We need to choose 3 strong, clear key details.

Good choices:

#1: More than 70 percent of Earth’s surface is covered by water.
#2: The Pacific Ocean is the largest ocean on Earth.
#3: Scientists have only explored part of the ocean — there is still so much left to explore.

*(Alternatively, you could pick “Different animals live in different parts of the ocean...” or “Water flows between the oceans...” — any 3 supporting facts work.)*

But let’s stick with these 3 because they are distinct and directly stated.

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Final check:

Topic: the ocean ✔
Main idea: The ocean is important to all living things. ✔
Key Details:
#1: More than 70% of Earth’s surface is covered by water.
#2: The Pacific Ocean is the largest ocean on Earth.
#3: Scientists have only explored part of the ocean — there is still so much left to explore. ✔

All match the text.

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Final Answer:
The topic of the text is: the ocean
The main idea of the text is: The ocean is important to all living things.
Key Detail #1: More than 70 percent of Earth’s surface is covered by water.
Key Detail #2: The Pacific Ocean is the largest ocean on Earth.
Key Detail #3: Scientists have only explored part of the ocean — there is still so much left to explore.