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 11 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.
A salmon returns to the river where it hatched.
Frogs change shape as they grow.
Swallows leave Britain to follow their food.
Trees help keep soil in place.
A.It finds the river by its smell.
B.Their roots hold the earth together in heavy rain.
C.Flying insects disappear in October.
D.A tadpole grows back legs before front legs.
2.Write the letter of the key detail that supports each main idea.
A canal lock lets boats climb hills.
Beavers change rivers by building dams.
Yeast makes bread rise.
Louis Braille invented a way for blind people to read.
A.He used a cell of six raised dots.
B.It gives off gas that is trapped in the dough.
C.Water flows in and the boat rises with it.
D.They pile up sticks and mud until the water backs up.
3.Write the letter of the key detail that supports each main idea.
Morse code turns letters into short and long signals.
Bees work together to run the hive.
Volcanoes form where melted rock escapes from the Earth.
Cheese is made by separating the protein in milk.
A.Some bees collect nectar while others guard the door.
B.Lava pours out through a crack and cools into rock.
C.Rennet splits the milk into curds and whey.
D.E is one dot and T is one dash.
LessonPrint · RI.3.2 · Set 11 · free to copy for classroom use
Answer key — Main Idea and Key Details
Set 11. Prints on its own sheet.
1.1. A salmon returns to the river where it hatched. — A (It finds the river by its smell.) 2. Frogs change shape as they grow. — D (A tadpole grows back legs before front legs.) 3. Swallows leave Britain to follow their food. — C (Flying insects disappear in October.) 4. Trees help keep soil in place. — B (Their roots hold the earth together in heavy rain.)
2.1. A canal lock lets boats climb hills. — C (Water flows in and the boat rises with it.) 2. Beavers change rivers by building dams. — D (They pile up sticks and mud until the water backs up.) 3. Yeast makes bread rise. — B (It gives off gas that is trapped in the dough.) 4. Louis Braille invented a way for blind people to read. — A (He used a cell of six raised dots.)
3.1. Morse code turns letters into short and long signals. — D (E is one dot and T is one dash.) 2. Bees work together to run the hive. — A (Some bees collect nectar while others guard the door.) 3. Volcanoes form where melted rock escapes from the Earth. — B (Lava pours out through a crack and cools into rock.) 4. Cheese is made by separating the protein in milk. — C (Rennet splits the milk into curds and whey.)
More practice for RI.3.2
State the main idea and show which details hold it up.