The sentence "She ate a ham sandwich for lunch." does not support the main idea of Maria helping her mother clean the house. The other sentences describe cleaning activities while that sentence simply describes Maria eating lunch, which is unrelated to cleaning.

1. Main idea &
Supporting Details

2. The MAIN IDEA is what the text
is mostly about.
The SUPPORTING DETAILS support
the main idea.
But first….let’s look at TOPIC.
 A Main Idea
 A Supporting Detail
 A Topic

3. What is a Topic?
A TOPIC is the
word or phrase
that everything
in a text refers
back to.

4. Looking for a Topic in Text
Water is an amazing resource.
Everyone in the world depends
upon it. Every creature needs
water to survive. Without water,
we would not last long. Water
makes our world beautiful.

5. The Topic is Water
Water is an amazing resource.
Everyone in the world depends
upon it. Every creature needs
water to survive. Without
water, we would not last long.
Water makes our world
beautiful.

6. Look for repeated words
In the last
paragraph, the
word water
was repeated
again and
again.

7. Finding Main Ideas
Once we have
found the topic
of the
paragraph, we
can find the
main idea.

8. Can you find the Main Idea?
Water is an amazing resource.
Everyone in the world depends
upon it. Every creature needs
water to survive. Without water,
we would not last long. Water
makes our world beautiful.

9. Can you find the Main Idea?
Water is an amazing resource.
Everyone in the world depends
upon it. Every creature needs
water to survive. Without water,
we would not last long. Water
makes our world beautiful.

10. Can you find the Main Idea?
Water is an amazing resource.
Topic + Main Point about the Topic = MAIN IDEA

11. Finding Main Ideas
Notice that topics are
expressed as words or
phrases, but main ideas are
expressed in sentences.

12. Main Idea at the Beginning
In textbooks, the main idea is often stated in the first or
second sentence of the paragraph. The rest of the
paragraph then supports the main idea with details.
LOCATIONS OF THE MAIN IDEA
Supporting Detail
Supporting Detail
Supporting Detail
Supporting Detail
Main Idea
Supporting Detail
Supporting Detail
Supporting Detail
Main Idea
Introductory Detail
or

13. Main Idea at the Beginning
LOCATIONS OF THE MAIN IDEA
For shy people, simply attending class can be stressful. Several
strategies, though, can lessen the trauma of attending class for
shy people. Shy students should time their arrival to coincide with
that of most other class members—about two minutes before the
class is scheduled to begin. If they arrive too early, they may be
seen sitting alone or, even worse, actually forced to talk with
another early arrival. If they arrive late, all eyes will be upon them.
Before heading to class, the shy student should dress in the least
conspicuous manner possible—say, in the blue jeans, sweatshirt,
and sneakers that 99.9 percent of their classmates wear. That way
they won’t stand out from everyone else. They should take a seat
near the back of the room. But they shouldn’t sit at the very back,
since instructors sometimes make a point of calling on students
there.

14. Main Idea in the Middle
Sometimes the main idea appears in the middle of the
paragraph.
LOCATIONS OF THE MAIN IDEA
Introductory Detail
Introductory Detail
Supporting Detail
Supporting Detail
Main Idea

15. A television ad for a new sports car showed scenes of beautiful
open country that suggested freedom and adventure. The car never
appeared in the ad at all. An ad for a hotel chain showed a
romantic couple in bed together. They were obviously on vacation
and having a leisurely, romantic, sexy morning. As these ads
suggest, advertisers often try to sell products and services by
associating them with positive images rather than by providing
relevant details about the product or service. An ad giving the
car’s gas mileage, safety rating, or repair frequency would be more
important to a buyer, but it might not draw the viewer’s interest as
much as beautiful scenery. Similarly, details on the hotel’s prices
and service would be more informative than images of a
glamorous vacation. But the romantic couple gets people’s
attention and associates the hotel in the viewers’ minds with a
good time.
Main Idea in the Middle
LOCATIONS OF THE MAIN IDEA

16. Main Idea at the End
Sometimes all of the sentences in the paragraph will lead
up to the main idea, which is presented at the end.
LOCATIONS OF THE MAIN IDEA
Supporting Detail
Supporting Detail
Supporting Detail
Supporting Detail
Main Idea

17. Only about 1 percent of insect species are destructive to crops
and property. Nevertheless, this small group causes several billion
dollars of damage each year in the United States alone. Harmful
insects include household pests, such as termites; crop and livestock
pests, such as boll weevils; and hosts of disease-causing organisms,
such as mosquitoes infected with parasitic protozoa. Many insects,
on the other hand, are beneficial to human society. Some insects
pollinate fruit trees, flowers, and many field crops. Bees produce
honey and beeswax, silkworms form cocoons from which silk is
spun, and lac insects provide the raw material for commercial
shellac. Some kinds of insects are natural enemies of destructive
insects. For example, the larvae of certain wasps feed on caterpillars
that destroy plants. Clearly, insects are both harmful and
beneficial to human society.
Main Idea at the End
LOCATIONS OF THE MAIN IDEA

18. Main Idea at the Beginning and the End
LOCATIONS OF THE MAIN IDEA
Supporting Detail
Supporting Detail
Supporting Detail
Supporting Detail
Main Idea
Main Idea
Sometimes an author will state the main idea
near the beginning of the paragraph and then
emphasize it by restating it later in the paragraph.

19. An important result of medical advances is an increase in the
number of conditions thought to be of medical concern. In the not-
to-distant past, birth and death usually occurred at home. Family
members and friends were there or close by. Now most people are
born and die in a hospital, surrounded by bright lights and expensive
machines. People who were addicted to alcohol or drugs were once
considered sinful or lacking in willpower. Now they are considered
“sick.” Problems that used to be accepted as part of life—baldness,
wrinkles, small breasts, sleeplessness—are now deemed proper
matters for medical attention. Some criminologists have even defined
antisocial behavior as a medical problem. Lawbreakers of all kinds,
from the shoplifter to the mass murderer, may potentially be labeled
“sick.” Because of current medical knowledge, what were once
thought to be problems of life or of character are now considered
medical issues.
Main Idea at the Beginning and the End
LOCATIONS OF THE MAIN IDEA

20. Supporting
Details

21. Supporting details give
more information related
to the main idea.
What are the supporting details
here?
Homeless people have many
problems. In winter, it’s hard to
stay warm and it gets too hot in
summer. It’s also hard to keep
things safe without a home. Worst
is the lack of privacy.

22. “Maria offered to help her mother
clean the house. She vacuumed
the living room and dusted the
furniture. She picked up the toys
in the playroom. She ate a ham
sandwich for lunch. Then, she
mopped the kitchen floor.”
Find the sentence that does not
support the main idea.

23. “Winter provides the opportunity for many
outdoor activities. Many people enjoy ice
skating on a pond. Swimming in the pond in
summer can also be fun. Skiing can be a
thrilling experience too. After a new snowfall,
you can even build a snowman!”
Find the sentence that does not support
the main idea.