Beacon Lesson Plan Library

What's the Big Idea? (Elementary School)

Kevin Hall


Students identify the main idea of a paragraph and supporting details. Students compose paragraphs by providing detail sentences for a given topic.


The student understands explicit and implicit ideas and information in fourth-grade or higher texts (for example, knowing main idea or essential message, connecting important ideas with corresponding details, making inferences about information, distinguishing between significant and minor details, knowing chronological order of events).

The student uses supporting ideas, details, and facts from a variety of sources to develop and elaborate the topic.


-Internet-connected computer(s) to access Student Web Lesson, Get the Idea (See Weblinks)
-Paper and pencil
-Prepared paragraphs (See Procedures for samples)


1. Check the Internet site to verify connectivity.
2. Write sample main ideas on the board, or generate your own to use.
3. Prepare detail sentences to support any new main ideas generated.



1. Have students complete the Web lesson, Get the Idea (See Weblinks) during their computer rotation time.

2. After completing the lesson, students complete one of the following activities:

a. Get a book of your choice. (One you’ve already read or would like to read.) First, choose a paragraph and find the main idea of that paragraph. Next, copy the paragraph on a sheet of paper. Then, identify the main idea by underlining it or highlighting it with a marker. Finally, make an illustration of the main idea to share. Be creative and have fun!

b. Write your own paragraph about a topic that interests you and illustrate it. (Remember to include a main idea and support it with detail sentences.) Swap your paragraph with a partner. Read your partner's paragraph and identify the main idea by underlining it or highlighting it with a marker. Return the paragraph to your partner and let him “check” to see that you found the main idea they thought they were writing!

3. Students turn in their completed paragraphs and illustrations. (See Assessment 2)


1. Write four or five main ideas on the board. (Generate ideas that relate to current classroom studies and interests, or use the following sample ideas):

-Going to a football game is fun.
-Camping out is an adventure.
-Making popscicles is easy.
-Once I flew on a jet.
-Doing well in school is up to you.

2. Tell the students that these are main ideas or topic sentences. Explain that the rest of the sentences in a paragraph are detail sentences that give more information or tell about the main idea.

3. Read the following sentences one at a time to the class. Call on students to tell which main idea the read sentence belongs with.

(OPTION: These sentences can also be typed on a worksheet or handout and given to the students. Students read the detail sentences and identify the main idea to which they belong. The paragraphs are then rewritten using the main idea and related details. Remind students that the detail sentences must occur in a logical order.)

-You can cook your dinner over a fire.
-You can cheer for your favorite team.
-Take off is fun, and landing is scary.
-First make the drink or juice that you are going to freeze.
-Listen to the teacher.
-The flight attendant brings you snacks.
-You can bird watch or catch fish.
-Next pour the juice into the plastic molds.
-It is important to do your homework.
-The food at the game is tasty.
-Sleeping in a tent is fun.
-The bathrooms are tiny.
-It is exciting when your team scores a touch down.
-Studying for a test helps you get a good grade.
-Next put the molds in the freezer.
-There are trails to explore.
-You should keep your seatbelt buckled during the flight.
-There are stands that sell souvenirs.
-Try to get a window seat if you can.
-After they are frozen, take them out of the freezer.
-Always do your homework.
-Even if your team loses, it is still fun.
-Obey the rules in your classroom.
-Watch out though, the animals might steal your food while you are sleeping.
-Finally, enjoy your frozen treat.

4. Invite students to make up a detail sentence to go under one of the the topic sentences.

5. Allow students an opportunity to read their paragraphs from the assessment to the class.


Have the students support one of the following main ideas. They should copy the sentence from the board or overhead and then write four or more detail sentences to complete the paragraph.

1. There are a lot of things to do after school.
2. Staying home sick is not all bad.

Assess students' paragraphs to see that they:
a. focus on the chosen topic sentence,
b. use supporting ideas, details, and facts to develop and elaborate the topic, and
c. follow the conventions of punctuation, capitalization, and spelling appropriate to grade level.

Assess the paragraphs completed in the follow-up activity of the Student Web Lesson to see that students correctly identified the main idea or essential message of the paragraph. Use this information as a formative assessment to direct any reteaching needed to help students understand main ideas and detail sentences.

Web Links

Web supplement for What's the Big Idea?
"Get the Idea"

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