Teaching the Difference Between Topic and Main Idea

Do you cringe when you start planning your nonfiction reading unit because you dread teaching topic versus main idea? You aren’t alone! This part of a nonfiction unit can be really challenging for elementary students.

Let’s dig right into some quick tips for teaching the difference between topic and main idea in grades 3-5.

Why Topic and Main Idea Are Tricky for Students

When I started teaching fourth grade, I found that my students could usually identify the topic of an informational text. Where they had trouble was telling me the main idea about that topic that the author was trying to communicate.

So for example, if they read a page about cats, they could tell me the topic was cats. And then I’d ask what the main idea was and they would say “cats.” Or “stuff about cats.” Or “it was about cats.” But they weren’t telling me WHAT about cats the author wanted them to know.

On the other hand, sometimes I’d have a student who went too specific or too broad – like latching on to just one tiny detail from the text or giving me a summary of everything they’d read.

I figured out pretty quickly that my students really needed scaffolded practice with the concept of topic versus main idea to understand what these terms really mean.

The Difference between Topic and Main Idea

Here’s what I wanted students to learn:

• The topic is the subject of the text. It’s short and we can say it with just a word or simple phrase. It’s general.
• The main idea is what the author wants you to know about the topic. It’s a complete sentence that includes a whole idea. It’s the big takeaway that you learned from reading. It’s more specific.

Activities to Teach Topic Versus Main Idea

So how do you get students to understand the difference? What worked for me was using lots of differentiated activities.

We started by looking at topic and main idea examples to see how they’re formatted (one or two words for a topic compared to a whole sentence for the main idea).

This helped them see that they could probably tell someone the topic of a nonfiction text without having to read it. Clues like the heading or title, pictures, and bold print give it away. But they couldn’t tell someone the main idea unless they actually read the text.

Visual aids and graphic organizers are a great way to model this. One example is using a small sticky note to write a topic and an index card to write the main idea.

Next, we created topic and main idea anchor charts with definitions and examples. And I kept these up all year long!

Practice Activities

Once my students really had the terms down, it was time for lots of practice with identifying the topic and main idea.

This included reading short nonfiction passages, of course, but also engaging activities like hands-on sorts.

I’ve also found it helpful to give students several texts that are all about the same topic but have very different main ideas. The passages in my ice cream-themed topic and main idea activities are great for that!

Reinforce in Writing Workshop

You can also carry this idea over to writing workshop. You can have your students all write about the same topic and then compare their pieces to see how each writer came up with a unique main idea about it. (P.S. I love using The Important Book by Margaret Wise Brown as a mentor text.)

Lots of explicit, differentiated practice with topic and main idea was what really made the difference in my classroom. I hope you’ve found a few tips to help you reach those students who struggle with this skill as you teach a nonfiction unit. Leave me a note in the comments if you have other strategies that you love!