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 2 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.
Yeast makes bread rise.
Bees work together to run the hive.
Morse code turns letters into short and long signals.
Frogs change shape as they grow.
A.E is one dot and T is one dash.
B.Some bees collect nectar while others guard the door.
C.A tadpole grows back legs before front legs.
D.It gives off gas that is trapped in the dough.
2.Write the letter of the key detail that supports each main idea.
Swallows leave Britain to follow their food.
Beavers change rivers by building dams.
A salmon returns to the river where it hatched.
Trees help keep soil in place.
A.They pile up sticks and mud until the water backs up.
B.It finds the river by its smell.
C.Their roots hold the earth together in heavy rain.
D.Flying insects disappear in October.
3.Write the letter of the key detail that supports each main idea.
Louis Braille invented a way for blind people to read.
A canal lock lets boats climb hills.
Lighthouses keep ships away from rocks.
Volcanoes form where melted rock escapes from the Earth.
A.Lava pours out through a crack and cools into rock.
B.Their lamps flash a pattern sailors can see at night.
C.Water flows in and the boat rises with it.
D.He used a cell of six raised dots.
LessonPrint · RI.3.2 · Set 2 · free to copy for classroom use
Answer key — Main Idea and Key Details
Set 2. Prints on its own sheet.
1.1. Yeast makes bread rise. — D (It gives off gas that is trapped in the dough.) 2. Bees work together to run the hive. — B (Some bees collect nectar while others guard the door.) 3. Morse code turns letters into short and long signals. — A (E is one dot and T is one dash.) 4. Frogs change shape as they grow. — C (A tadpole grows back legs before front legs.)
2.1. Swallows leave Britain to follow their food. — D (Flying insects disappear in October.) 2. Beavers change rivers by building dams. — A (They pile up sticks and mud until the water backs up.) 3. A salmon returns to the river where it hatched. — B (It finds the river by its smell.) 4. Trees help keep soil in place. — C (Their roots hold the earth together in heavy rain.)
3.1. Louis Braille invented a way for blind people to read. — D (He used a cell of six raised dots.) 2. A canal lock lets boats climb hills. — C (Water flows in and the boat rises with it.) 3. Lighthouses keep ships away from rocks. — B (Their lamps flash a pattern sailors can see at night.) 4. Volcanoes form where melted rock escapes from the Earth. — A (Lava pours out through a crack and cools into rock.)
More practice for RI.3.2
State the main idea and show which details hold it up.