# Discover! Simulations

## Motion and Forces

### 1. Get Set to Explore

#### Vocabulary

• magnet: A kind of object containing a metal that allows the object to attract and repel certain other metal objects.
• pole: The place on a magnet where the magnetic force is the strongest; each magnet has a north pole and a south pole.

#### Building Background

• Review the vocabulary words and definitions with the class.
• Go over the four main geographic directions with the class: north, south, east, and west. You may wish to put up signs or have children put up signs around your classroom identifying the four directions.
• Show children a simple compass, and pass around one or more compasses. Direct children to notice what happens to the compass needle as they move the compass. Guide them to realize that the needle always points in one direction. Elicit the fact that this direction is north.
• Ask children why the compass needle always points north. You might give the class the hint that Earth is a giant magnet. Explain that the simulation will help them figure out or confirm the answer to this question.
• Pose the Discover! question: How can a magnet keep you from getting lost? Write children's ideas on the board.

### 2. Guide the Exploration

• Tell children to launch the Discover! Simulation. They should listen closely to the question and the directions.
• Children should spend some time moving the compass around the magnet and observing how the compass needle changes position. Once they understand how the compass needle moves, they should click on Earth or Map to continue the simulation.
• If children have trouble understanding why the compass needle always points to the north when they move it around Earth, have them click the north pole of the magnet and review what happens with the compass needle as they move the compass around the magnet. Guide children to see the similarity between what happens when they move the compass around the magnet and when they move it around Earth.
• When children are working on the Map part of the simulation, you may wish to direct them first to use the compass to figure out which way is north on the map. Note that when children are figuring out in which direction they need to travel to reach a specific place, they should imagine that they are standing at the center of the map, at the crossroads.

### 3. Review/Assess

• Go over Step 3's Wrap-Up text with the class. Guide children to understand that if they know which direction is north, they can figure out the other three directions. In this way, a compass could help them find their way and not get lost.
• Present the Extension question to the class.
• To travel from the crossroads to the cabin, children would go west.
• To travel from the crossroads to the mountain, children would go south.
• To travel from the crossroads to the campground, children would go east.

If time permits, present children with the following questions:

• Critical Thinking: Synthesize Maps are pieces of paper and, so, are not magnetic. What does a map need to have in order for you to be able to use the map to figure out directions? Answer: It needs to indicate which direction is north (or any of the other compass directions).
• Inquiry Skill: Communicate In which direction do you live from school? Use the compass to help you figure it out. Then pair up with a classmate and explain how you used the compass to figure out the answer. Answer: Answers will vary depending on where children live. You may wish to introduce the intermediate directions—northeast, southeast, northwest, and southwest—to aid children in answering the question.

### 4. Reaching All Learners

#### Challenge

Encourage children to use a compass to help them make an accurate map of the classroom, the school grounds, or their route from home to school. If children map the classroom, give them a measuring tape so that they can draw the map to scale. Most importantly, have children indicate directions accurately using the compass and a ruler and perhaps a right-angle measure.