Learn to find the big picture and the facts that support it
The main idea is the most important point of a text. It tells you what the whole text is about in one or two sentences.
Think of it like this: if you tell a friend about something you read, and you can only say one sentence, that sentence is the main idea.
The main idea = the big message the author wants you to understand.
The main idea can sometimes be found in:
Supporting details are the facts, examples, reasons, or descriptions that explain the main idea or prove it is true.
Think of a table. The main idea is the top of the table. The supporting details are the legs that hold it up. Without the legs, the table falls!
Facts: things that are true and can be proven.
Examples: specific situations that show the main idea.
Reasons: explanations for why something is true.
Descriptions: words that help you picture or feel something.
Simple example:
Dogs are great pets.
• They are friendly and loyal.
• They can learn tricks.
• They help people feel less lonely.
Follow these steps when you read any text:
"What is this text mostly about?" → Main Idea
"What facts or examples does the author give?" → Supporting Details
"Why should I believe the main idea?" → Supporting Details
Now read the text below. Try to find the main idea and the supporting details as you read.
Which sea creature eats most of its food during the summer, likes to sing and dance, and is as big as a bus? If you guessed the humpback whaleA large type of whale known for its beautiful songs and jumping behaviour, you are correct. The humpback whale is truly an amazing creature.
Humpback whales live in groups called podsA group of whales that swim and live together. Pods swim in oceans all over the world, spending summer months along the coastlines. There they feed on krillA very small sea animal that looks like a shrimp (a small, shrimp-like animal), planktonTiny sea plants and animals that float in water (a sea plant), and other small fish. They use a filtering system to eat. Water flows into their mouths through two rows of baleen platesHard plates inside a whale's mouth used to filter food from water. The plates catch food but let the water back out. Then the food goes to the whale's stomach to be digested.
During the winter months, humpbacks swim to warmer waters near the equatorAn imaginary line around the middle of the Earth where the weather is warm to mate. When humpbacks mate, the male humpbacks often "sing" to attract the females. Once a female becomes pregnant, it takes about a year before its baby is born. Newborn humpbacks stay close by their mothers. Scientists have noticed that mother and baby always seem to be touching each other — perhaps as a sign of affection.
Humpback whales are known for leaping out of the water. Scientists do not know whether they do this just for fun, or for a more practical reason, such as to clean themselves. In either case, the whales use their large tail fins, or flukesThe flat, wide parts of a whale's tail, to throw themselves out of the water and into the air, before landing with a big splash.
There are about 30,000 to 40,000 humpback whales today. Scientists keep track of individual whales by looking at the white markings on their bellies. Each whale has unique markings, so scientists are able to identify it. Scientists gather information such as the whale's size, its songs, and where it travels.
💡 Tip: Hover over the blue dashed words to see their meaning!
Let's use our steps to find the main idea and supporting details.
The title is "A Fascinating Creature." This tells us the text is about an interesting animal. But which one? We need to read more to find out.
The first paragraph says: "The humpback whale is truly an amazing creature." This sentence tells us the whole point of the text. This is our main idea!
Now we ask: "What facts does the author give to show that humpback whales are amazing?" The rest of the text gives us many details! Let's look at them below.
Look at the highlighted version below:
Which sea creature eats most of its food during the summer, likes to sing and dance, and is as big as a bus? If you guessed the humpback whale, you are correct. The humpback whale is truly an amazing creature.
Humpback whales live in groups called pods. Pods swim in oceans all over the world, spending summer months along the coastlines. There they feed on krill, plankton, and other small fish. They use a filtering system to eat. Water flows into their mouths through two rows of baleen plates. The plates catch food but let the water back out.
During the winter months, humpbacks swim to warmer waters near the equator to mate. When humpbacks mate, the male humpbacks often "sing" to attract the females. Once a female becomes pregnant, it takes about a year before its baby is born. Newborn humpbacks stay close by their mothers. Scientists have noticed that mother and baby always seem to be touching each other — perhaps as a sign of affection.
Humpback whales are known for leaping out of the water. Scientists do not know whether they do this just for fun, or for a more practical reason, such as to clean themselves.
There are about 30,000 to 40,000 humpback whales today. Scientists keep track of individual whales by looking at the white markings on their bellies. Each whale has unique markings, so scientists are able to identify it.
Each paragraph has its own small main idea and supporting details too. Let's look at each one:
The humpback whale is a truly amazing creature.
This paragraph introduces the topic with an interesting question to get your attention.
Humpback whales have a special way of eating.
• They live in groups called pods.
• They eat krill, plankton, and small fish.
• They use baleen plates to filter food from water.
Humpback whales have interesting mating and family behaviours.
• In winter, they swim to warm water to mate.
• Males "sing" to attract females.
• Baby whales are born after about one year.
• Mothers and babies always touch each other.
Humpback whales are famous for jumping out of the water.
• Scientists don't know if they jump for fun or to clean themselves.
• They use their tail fins (flukes) to leap into the air.
• They land with a big splash.
Scientists study and track humpback whales.
• There are 30,000 to 40,000 humpback whales today.
• Each whale has unique white markings on its belly.
• Scientists use these markings to identify individual whales.
• They collect information about size, songs, and travel routes.
Main Idea = The most important message. What is the text mostly about?
Supporting Details = The facts, examples, and reasons that explain or prove the main idea.
In "A Fascinating Creature":
🐋 Main Idea: The humpback whale is a truly amazing creature.
🧩 Supporting Details: They eat using baleen plates, males sing, mothers are affectionate, they leap out of the water, and scientists track them by their unique markings.
Now let's check your understanding. Click the answer you think is correct.