Howard County Schools
Constant Rate Exploration
Question: What do rectangles and bathtub volume have in common? Answer: Linear equations. Learn how to identify situations that have constant rates by examining two different situations, one proportional and one not proportional.
CK-12 Foundation
Ck 12: Statistics: Double Line Graphs
[Free Registration/Login may be required to access all resource tools.] Construct and interpret double line graphs.
Better Lesson
Better Lesson: The Double Number Line
The double number line will help students figure out problems that involve two quantities.