Main Idea and Key Details is a free printable Grade 3 English worksheet on matching a main idea to the key detail that supports it, aligned to Common Core standard RI.3.2. It prints 3 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 22 of 25 · the same problems every time you open this link.
Set 1 has all 25 in a single PDF. All 25 sets ask different questions.
Main Idea and Key Details
RI.3.2
NameDate
Write the letter of the detail next to each main idea.
1.Write the letter of the key detail that supports each main idea.
Trees help keep soil in place.
A salmon returns to the river where it hatched.
Bees work together to run the hive.
Louis Braille invented a way for blind people to read.
A.Their roots hold the earth together in heavy rain.
B.It finds the river by its smell.
C.Some bees collect nectar while others guard the door.
D.He used a cell of six raised dots.
2.Write the letter of the key detail that supports each main idea.
Beavers change rivers by building dams.
Morse code turns letters into short and long signals.
Yeast makes bread rise.
Cheese is made by separating the protein in milk.
A.It gives off gas that is trapped in the dough.
B.E is one dot and T is one dash.
C.They pile up sticks and mud until the water backs up.
D.Rennet splits the milk into curds and whey.
3.Write the letter of the key detail that supports each main idea.
A windmill turns moving air into turning stone.
Volcanoes form where melted rock escapes from the Earth.
Lighthouses keep ships away from rocks.
Swallows leave Britain to follow their food.
A.Lava pours out through a crack and cools into rock.
B.Their lamps flash a pattern sailors can see at night.
C.Flying insects disappear in October.
D.The sails turn a shaft that turns the millstone.
LessonPrint · RI.3.2 · Set 22 · free to copy for classroom use
Answer key — Main Idea and Key Details
Set 22. Prints on its own sheet.
1.1. Trees help keep soil in place. — A (Their roots hold the earth together in heavy rain.) 2. A salmon returns to the river where it hatched. — B (It finds the river by its smell.) 3. Bees work together to run the hive. — C (Some bees collect nectar while others guard the door.) 4. Louis Braille invented a way for blind people to read. — D (He used a cell of six raised dots.)
2.1. Beavers change rivers by building dams. — C (They pile up sticks and mud until the water backs up.) 2. Morse code turns letters into short and long signals. — B (E is one dot and T is one dash.) 3. Yeast makes bread rise. — A (It gives off gas that is trapped in the dough.) 4. Cheese is made by separating the protein in milk. — D (Rennet splits the milk into curds and whey.)
3.1. A windmill turns moving air into turning stone. — D (The sails turn a shaft that turns the millstone.) 2. Volcanoes form where melted rock escapes from the Earth. — A (Lava pours out through a crack and cools into rock.) 3. Lighthouses keep ships away from rocks. — B (Their lamps flash a pattern sailors can see at night.) 4. Swallows leave Britain to follow their food. — C (Flying insects disappear in October.)
More practice for RI.3.2
State the main idea and show which details hold it up.