Reading nonfiction: main idea and key details (grade 4) · lesson

Key details

💡 Answer with the exact fact the text gives, and find the sentence that says it.

Key details are the facts that matter: what something is made of, when it happens, or what someone does next.

Find a word from the question in the text. Then read that whole part, not just one line.

Watch for words like after, first, and when. They tell you which part of a process the question means.

🧠 Let's work it out

Question: What does a spider do after it spins a web?

Find spins in the text.
The text says: It spins a web. Then it waits in the center for bugs.
Ask: what comes after the spinning? It waits in the center.
That is the answer.

What do you think comes next?

key detail: an important fact in the text

🔗 Key ideas and details, long passages (grade 4) · Khan Academy ↗

Explain how and why

💡 Science and history texts explain how something works and why it happens, often step by step.

Some texts tell a process. A process is a set of steps. Each step leads to the next.

Other texts tell why. Look for words like because, so, for this reason, and this helps.

To answer a why question, find the result in the text. Then look before it for the cause.

🧠 Let's work it out

Text: A camel stores fat in its hump. For this reason, it can go for days without food in the desert.

Ask: how can a camel go days without food?
Look before for this reason.
It stores fat in its hump.
So the hump works like a food supply.

What do you think comes next?

process: a set of steps that happen in order
cause: why something happens

Main idea

💡 The main idea is the point that most of the paragraphs support.

The main idea is the most important point about the topic. It is bigger than any one fact.

Ask what most of the paragraphs tell about. Then say it in one sentence.

Be careful. A choice that is true, but only fits one paragraph, is a detail.

🧠 Let's work it out

A text about whales has parts on how they breathe, how they talk with sounds, and how they find food.

Ask: what ties these together?
They all tell how whales live in the ocean.
So the main idea is that whales have ways to live in the sea.
How they breathe is only one detail.

What do you think comes next?

main idea: the most important point of a text

Summarize a paragraph

💡 A good summary keeps the big idea and leaves out the small details.

To summarize means to tell the most important part in a few words.

Look at the first sentence of the paragraph. It often states the point. The other sentences give examples.

A good summary covers the whole paragraph. It does not pick just one example.

🧠 Let's work it out

Paragraph: Walking to school is good for kids. It gets their legs moving. It wakes up their minds. It also saves gas.

Ask: what is the point? Walking to school is good for kids.
The rest are examples.
So a summary is: walking to school helps kids and saves gas.

What do you think comes next?

summarize: to tell the main points in a few words

Details that support an opinion

💡 An author supports an opinion with reasons, and each reason is backed by details.

In an opinion piece, the author's main opinion is often in the first paragraph.

Each reason gets its own paragraph. The details in that paragraph back up that reason.

To find details for a reason, go to the paragraph that starts that reason. Pick details that prove it, not details about some other reason.

🧠 Let's work it out

Text: Every park should have a water fountain. First, it keeps people healthy. Runners can drink when they are thirsty, and kids do not get too hot.

Ask: what is this reason? Staying healthy.
Which details prove it? Runners get a drink, and kids stay cool.
Both are about health.

What do you think comes next?

opinion: what someone believes
support: to back up with reasons and facts