Main Idea and Its Support is a free printable Grade 4 English worksheet on working out a main idea from the details that support it, aligned to Common Core standard RI.4.2. It prints 8 questions with an answer key on its own sheet of paper, in 25 versions that each ask different questions, so no two students in the class work from the same page. Print it from the browser or download it as a PDF — no account, no email.
Set 1 of 25 · the same problems every time you open this link.
1.A paragraph says: coral reefs cover a tiny part of the sea floor; a quarter of all sea creatures live on them; many fish lay their eggs there. What is its main idea?
A.Coral reefs are home to a great deal of sea life.
B.Fish lay eggs.
C.Coral reefs are very small.
2.A paragraph says: trains ran to schedules across the country; each town had kept its own time; the railways needed one time everywhere. What is its main idea?
A.The railways led to one time for the whole country.
B.Trains were often late.
C.Towns had clocks.
3.A paragraph says: beavers fell trees with their teeth; they build dams of sticks and mud; their ponds give homes to fish and birds. What is its main idea?
A.Fish live in ponds.
B.Beavers have sharp teeth.
C.Beavers change the places where they live.
4.A paragraph says: some volcanoes pour out rivers of lava; others explode in clouds of ash; some have been quiet for thousands of years. What is its main idea?
A.Lava is hot.
B.Volcanoes behave in different ways.
C.Ash is gray.
5.A paragraph says: libraries lend books for free; many offer computers anyone can use; they run reading clubs for children. What is its main idea?
A.Computers are useful.
B.Libraries offer many free services to a town.
C.Children like clubs.
6.A paragraph says: lighthouses warn ships away from rocks; each one flashes its own pattern; sailors use the pattern to tell where they are. What is its main idea?
A.Lights can flash.
B.Lighthouses keep ships safe and help them find their way.
C.Rocks are dangerous.
7.A paragraph says: honeybees carry pollen from flower to flower; without them many fruits would not grow; farmers rent hives for their orchards. What is its main idea?
A.Farmers keep hives.
B.Flowers have pollen.
C.Bees are important for growing food.
8.A paragraph says: plastic bags take hundreds of years to break down; turtles mistake them for jellyfish; many towns now charge for bags. What is its main idea?
A.Stores sell bags.
B.Turtles eat jellyfish.
C.Plastic bags harm the natural world.
LessonPrint · RI.4.2 · Set 1 · free to copy for classroom use
Answer key — Main Idea and Its Support
Set 1. Prints on its own sheet.
1.Coral reefs are home to a great deal of sea life.
2.The railways led to one time for the whole country.
3.Beavers change the places where they live.
4.Volcanoes behave in different ways.
5.Libraries offer many free services to a town.
6.Lighthouses keep ships safe and help them find their way.
7.Bees are important for growing food.
8.Plastic bags harm the natural world.
Questions about Main Idea and Its Support
What does the Main Idea and Its Support worksheet cover?
It practices working out a main idea from the details that support it — 8 questions for Grade 4, all on Common Core RI.4.2: State the main idea, show the details behind it, and summarize. The instruction to students is “Circle the right answer”, and the answer key follows on the next sheet.
Which Common Core standard does Main Idea and Its Support practice?
CCSS.ELA-LITERACY.RI.4.2 — RI.4.2, under Reading: Informational Text for Grade 4. The published standard reads: “Determine the main idea of a text and explain how it is supported by key details; summarize the text.” The worksheet assesses that standard rather than a paraphrase of it.
What age or grade is this worksheet for?
Main Idea and Its Support is written for Grade 4, typically ages 9-10. It is one of the sheets on RI.4.2, so it suits any student working at that standard — including older students revisiting it and younger ones working ahead.
Does Main Idea and Its Support come with an answer key?
Yes. All 8 answers are generated from the same problems as the questions, so the key cannot drift out of step with the sheet. It starts on a fresh sheet of paper, after the questions, so it is not handed out with the class by accident.
How many different versions of Main Idea and Its Support can I print?
25 — one per student, and all 25 ask different questions. Set 1 downloads the whole class as a single PDF. Every version is fixed to its own address, so a sheet printed today holds the same problems when you reopen it next week.
Is Main Idea and Its Support free to print and photocopy?
Yes. Main Idea and Its Support, its answer key and its 25 versions are free to print and photocopy for your own class, with no account, no email capture and no subscription at the download step. Please do not resell them or republish them as your own.
Is there a lesson plan to teach RI.4.2?
Yes — “The Main Idea and a Summary” is a 40-minute Grade 4 plan for RI.4.2, timed section by section, with the misconceptions to expect and an exit ticket. Main Idea and Its Support is the practice that follows it.
More practice for RI.4.2
State the main idea, show the details behind it, and summarize.
Teaching this next? The Main Idea and a Summary is the 40-minute plan for it, with the misconceptions to expect.