Main idea is an abstract concept and therefore hard for first graders. When reading expository text, they can give the key details, but usually just give another detail for a main idea. I had been thinking of ways to make the concept more concrete for my class and decided to try to present it as being what was common in every page (text or illustration) of an informational story.
I told my class that they were going to read an interesting story, and when they finished I wanted them to tell me what the main idea was, what the whole book was about. I reminded them that they should read expository text more than once, and that they should also pay attention to the photographs. After a few minutes, I asked who could tell me what the main idea was. As I expected ( I confess I avoided the most advanced students) the student I picked gave as main idea a detail about the animal he had found more interesting (it was a book about animal homes). I gave him several post-it notes and asked him to show us the evidence in the text. Of course, he could only place them on the page referring to that animal. I reminded them that the main idea could be found in all the pages (for some texts, you would need to modify this to say many or most of the pages, or paragraphs).
I sent them back to the text, each armed with a little stack of post-it notes to find the main idea. I said it would be like a treasure hunt.
They really enjoyed searching for the main idea. You can see an example in the resource section.
When I saw that most had used several post-it notes and had indeed searched through the book, I asked them to stop and called on several to tell me what they thought the main idea was. This is one of the instances where I like to remain non-committal after each answer so that more than one has an opportunity to share. I don't encourage repeating the previous answer just for the sake of saying something, but when they say (usually dejectedly) that they were going to say something already said, I ask them to tell it to us in their own way. We soon agreed that the main idea was that animals have different kinds of homes.
I then told them that I wanted them to complete a graphic organizer showing the main idea and three details. My students draw their own organizers because I want them to use them independently as tools. You can see how they do it in the clip in the resource section).This activity is another way to approach R.I.1 (Ask and answer questions about key details in a text. ) since they have to find text based answers. As I circulated I prompted with questions when a student seemed stuck, and reminded them to look for evidence from the text.
When most students had finished, my helper for the day and I collected the work. Then I restated our lesson's objective and called on students to share one key details they had found.