1. Print the items in the materials page.
2. Assign students to groups.
3. Number the student worksheets with station #s.
4. Assemble other materials - sticky notes.
5. Set up the wall chart.
6. Set up computer access for students or your single comptuer linked to a projection system.

1. Imagine that you are sitting in a totally dark room and you need to find the door without moving all around the room. How are you going to do it?
2. Have students briefly discuss and write their thoughts in their science notebooks.
3. Show safety features. 4. Show

1. Humans can't do this very well if at all without special tools.
2. Thus they need prepare for power outages by installing backup lights and exit signs that still work when power goes out.
3. Some animals, such as bats and dolphins, have natural capabilities to "see: in the dark using echolocation.
4. We can invent tools to help us "see" in the dark like bats. Like when we want to see clouds at night.

How does echolocation (or sonar) work?

1. Show video of bats in Deer Cave in Borneo and discuss key observations. 2. Show video of bats leaving their home caves at twilight and discuss key observations.
2. Discuss the reasons why bats might not go out and hunt during the day.
3. Speculate on the reason for their chaotic flight path.
Further study: 4. Reveal that many bats eat insects, although some eat fruit and small animals.
5. Show students local bats, population trends and discuss their benefits in insect control.
6. Listen to the sounds they produce to track down flying insects.

1. Show the animation of bat echolocation.
2. Explain how sound waves radiate outward from a source.
3. Point out that sound waves move at particular speed that is slow enough to fall noticeably behind light.
4. How does the bat know if a target is closeby or distant?
5. 5  Students review arithmetic operators, the structure of equations, how to deal with units and how to find a solution

Have students go to thei student website for this activity, or show them the Powerpoint slide.

1. Have students set up their diagram using the situation visualizer animation.
2. Discussion in group

1. Have students set up their equation using the equation visualizer animation.
2. Discussion in group
3. Have students write down their equations.

1. Ask students about what they want from their equation. What do they want to know?
2. Make sure that variable is isolated on the left side of the equation.
3. Show them how several equations describe the situation, but only one helps them isolate the item of interest.
4. To solve the problem, they must fill in all the items on the other side.
5. What is the speed of sound in air? Constant.
6. What is the distance to the ground? You can't measure so like a bat, you measure travel-time and figure out distance.
7. Explain that travel-time is a proxy for distance.
8. Remind them that the distance to the ground is not the elevation. Show them diagram.

1. Point out the data on each student's data sheet. Travel-time and distance along the line in miles from the starting point. 2. Point out the starting point on the wall chart. 3. Remind students that once each bat figures out the elevation beneath them, the combined information will produce the shape of the topography below.
4. Tell students to make their calculations on the worksheet and when they are finished to check each other's work and to place their bats and elevation postits on the wall chart.
5. If they are done, give them an alternative profile to interpret. 1. Each student is a bat.
2. The class of "bats" is arranged in a line and flying at night over unseeable territory in the dark.
3. The line of bats is flying at an elevation of 10,000 feet above sea level.
3. Together, the line of bats is going to use echolocation to determine the depth to the ground AND to visualize the shape of the underlying topography relative to sea level.
4. Once the topography is revealed, the class neeeds to guess where in the world they are located.