So, the key to finding main idea (and cockroaches) is to follow the clues (unless it's sitting right there on the kitchen counter). Main ideas don't hide like roaches. The main idea is usually just part of a larger collection of ideas.
- If you see a cockroach, you follow it to figure out where it goes. See whether it crawls into a crack or hole in the wall. The "nest" is likely close by. When reading, if you see a key word, look for a key phrase that uses that key word AND relates to the rest of the reading passage.
- With roaches, you might need to do a little sleuthing. Check all around the house for cracks and holes through which roaches may enter. Roaches often enter through drains or vents. With the main idea, check that first sentence. Sometimes writers put their main idea right in the front so it's obvious for readers. So, it's that simple. Sometimes. Other times, writers use supporting details to build up to the main idea.