Unit 7 Contents

8. Make a graph of your data on Centimeter Grid Paper.
• Graph the number of drops (N) on the horizontal axis and the area (A) on the vertical axis.
• The vertical axis should be numbered to at least 40 sq cm.
• What is the area of a spot made with zero drops? Add this point to your graph.
9. If the points on your graph suggest a line, use a ruler to draw a best-fit line.

Write the answers to these questions. Use your graph and your data table to help you.

1. Describe the graph. What does the graph tell you about the relationship between the number of drops and area?
2. How would a change in the number of drops affect area?
3. How would a change in area affect the number of drops?
1. Use your graph to predict the area of a spot made with three drops of water. Show your work on your graph and record your prediction.
2. Make a spot using three drops of water. Find the area.
3. Was your prediction close to the actual area? Explain why or why not.
1. Use your graph to predict the area of a spot made with five drops of water. Show your work on your graph and record your prediction.
2. Check your prediction by making a spot with five drops. Find the area of the spot.
3. Was your prediction close to the actual area? Explain why or why not.
1. If you want to make a spot with an area of 40 sq cm, how many drops should you use? Explain how you solved this problem.
2. Find another way to solve this problem. Explain.