Reading · Grade 3 Reading
Chapter 1: Main Idea and Details
The one idea that holds every sentence together.
The main idea of a paragraph is the one idea that holds every sentence in it together. Today you learn a test you can run yourself, instead of guessing what the answer is meant to be.
Today’s story
What a Beaver Does to a River
An article, in five parts. About 230 words.
One part at a time. Press Listen, or read it yourself. The tutor reads along with you.
The tutor shows
Teeth like chiselsA beaver’s front teeth never stop growing. They are orange, and they are harder on the front than on the back, so they wear into a chisel shape as the beaver gnaws. A beaver can bring down a willow as thick as your leg in a single night.
Why is “a beaver can fell a willow in a night” not the main idea of this part?
Building the damThe beaver does not eat most of the wood. It drags the branches into the stream and pushes them into a wall, packing the gaps with mud and stones until the water can no longer get through. This wall is called a dam.
The pond appearsBehind the dam, the stream stops running and spreads out. Within a few weeks there is a pond where there was once a narrow channel. The beaver builds its lodge in the middle of it, with the entrance underwater, where no fox can follow.
Who else moves inThe pond is not only for beavers. Frogs lay their eggs in the still water. Herons stand in the shallows and fish. Dragonflies hunt over the surface, and moss grows on the drowned trunks. A stretch of stream that held a handful of species now holds dozens.
And then a meadowOne day the beavers move on, and the dam breaks. The pond drains, and what is left is a flat bed of rich mud where the water stood. Grass takes it first, then flowers, then young trees. The place that was a stream, and then a pond, becomes a meadow.
Finish reading with the tutor, and the whole story appears here with its parts named.
Finish the story first. Then write down two things you noticed.
Main idea is usually assessed by agreement with an answer key, which teaches a child to guess the teacher rather than read the text. The two tests here can be run by the child alone: a main idea covers every sentence in the paragraph, and it does not cover paragraphs it has nothing to do with.
When your child names a main idea, ask them to check it against each sentence in turn. The checking is the lesson.