Main Idea Tuesday 1-24-12

FINDING THE MAIN IDEA

—  The main idea tells what the whole passage is about.  It is the main or most important point the writer wants to make.

—  When looking for the main idea read the title of the passage.  The title is written in BOLD at the top of the passage.  Find the title before you read the passage.  Read it and think about it by asking:

—  What is this reading all about?

—  What is the main point?

—  Why did the writer write this?

—  What information will I get from this reading?

—  What is the BIG picture here?

—  Why would someone want to read this?

—  The introduction is right under the title.  Just like the title, the introduction gives important information about what you are going to read.  Sometimes the introduction tells the main idea before you read. After you read the introduction, ask yourself:  Is there a topic sentence? 

A topic sentence explains in a few words what the passage is going to be all about.  When you find the topic sentence, you have found the stated main idea.

If the main idea is not stated, then it is implied. The implied main idea is only suggested. There is not topic sentence, so you need to be a good detective. Pay attention to details, and put them together with your own knowledge to determine the main idea.

Read the following paragraphs and choose the correct main idea for each paragraph.

1. There are several events that can change the Earth's surface very quickly. Volcanoes can erupt and spread lava, rock and ash for several miles.  Earthquakes can leave large cracks in the Earth's surface.        

What is the main idea?

1.  Several events can change the Earth's surface.
2. Earthquakes can cause large cracks. 

C.       Volcanoes can be dangerous.

2. Most of the world's volcanoes are part of the "The Ring of Fire." This is a ring of volcanoes that form a circle around the Pacific Ocean. Thousands of volcanoes make up "The Ring of Fire." These volcanoes formed the sea floor and many underwater mountains.

What is the main idea?

1. There are thousands of volcanoes in the world.
2. Most volcanoes are part of the "Ring of Fire."
3.  Some underwater mountains are volcanoes

3. Scientists can measure the intensity of an earthquake. They use an instrument called the Richter scale. The Richter scale compares the strength of different earthquakes. Earthquakes  below 2.0 usually can’t be felt. Earthquakes over 5.0 on the scale can cause damage. A magnitude 7.0 is a major earthquake and can cause tremendous damage.

What is the main idea?

1. Strong earthquakes can cause lots of damage.
2. Some earthquakes are very small. 
3. Scientists can measure the intensity of an earthquake.