This award-winning series helps students to build confidence in their ability to "do math" and develop the knowledge and skills required to become mathematically literate. This program combines arithmetic and geometry to provide knowledge essential for success in algebra. The coordinate plane is introduced using the example of latitude and longitude. Identification of points as ordered pairs is examined, as is construction of a line though given points in the plane. Equations of the type y = ax + b are associated with lines, and the significance of the signs of "a" and "b" is discovered. This is the basis for understanding slope and y-intercept in algebra. The usefulness of this lesson is demonstrated by using a "fit" line to model data. Students will learn to plot the point associated with an ordered pair and to plot points and draw the line that is the graph of an equation of the form y = ax + b.