Main Idea & Supporting Details — Answer Key
Part A: Sort the Words
Sort each word or number into the correct category box.
1. Read each sentence about dolphins. Decide if it is a main idea or a supporting detail.
Main Idea or General Statement
Dolphins are very smart animals.Dolphins are amazing ocean creatures.Dolphins are mammals that live in the sea. Supporting Detail
Dolphins use clicks and whistles to talk.Baby dolphins stay close to their mothers.Dolphins can jump high out of the water. The main-idea sentences describe dolphins in a big, general way, like calling them smart or amazing. The supporting details give one specific fact each, such as how they talk or how they jump.
Part B: Fill in the Blank
Write the missing word or number on each line.
1. Dolphins use clicks and whistles to talk to each other.
Dolphins make two main sounds: short clicks and higher whistles. The whistles are like calls they use to find family members and share messages.
2. The main idea tells the biggest message of a paragraph.
Out of everything in a paragraph, the main idea is the biggest or most important thought, while supporting details are the smaller pieces underneath it.
3. A detail about dolphins is that baby dolphins stay close to their mothers.
Baby dolphins, called calves, swim right next to their mothers so they stay safe and can drink milk. This is a specific detail, not the big main idea.
4. When you retell a passage, you say the main idea and the most important details.
A good retelling pairs the main idea with the key details that support it, so the listener understands both the big point and why it is true.
5. The topic of a passage about dolphins is dolphins.
The topic is simply the subject the passage is about. If every sentence is describing dolphins, then 'dolphins' is the topic.
Part C: True or False?
Read each statement. Circle True or False.
1. A supporting detail is the same as the main idea.
True False
The main idea is the big message, and supporting details are the smaller facts that prove it. They work together, but they do different jobs in a paragraph.
2. A passage about dolphins might have many details about how they live.
True False
Nonfiction passages usually share several details about an animal's home, food, family, and habits so readers learn a lot at once.
3. Reading the first sentence of a paragraph can help you find the main idea.
True False
Many writers put the main idea at the very start, called a topic sentence, so checking the first sentence is often a quick way to spot it.
4. Off-topic details help the reader understand the main idea better.
True False
Off-topic details are about something different, so they only confuse the reader instead of helping the main idea make more sense.