Given a linear set of points where the x coordinates increase by one, identify what the y coordinates are increasing by as a rate of prices rising or falling.
• Nemeth: understanding of a table of values as a way to represent multiple points and understanding of how to graph the points in a coordinate system, Delta symbol (meaning change), and subscript.
Graph paper
Dots, markers, Wikki Stix or other tactile method of conntecting coordinates
Review with the student the definition of ‘slope’. Using the YouTube Video “Slope Dude” and the Slope Dude pdf listen to the description of what slope does. Slope can be positve (increasing), negative (decreasing) or undefined.
Using the student’s graph from “Ice Cream in Winter” ask the student to identify the Line of Best Fit. (This should be a positive slope)
Ask the student to identify two points on the y-axis and two points on the x-axis which are on the Line of Best Fit. If the student has difficutly with idientifying these points, practice until the student is confident. Have the student record these points using the students media of choice
Review the formula for slope with the student (using the different verbiage). Formula for Slope = y2 – y1/x2 – x2 or Slope = the change in y/the change in x or Slope = rise/run
Have the student enter the coordinates into the formula. Have the student calculate the slope. A calculator can be used.
Explain to the student that the slope can be used to interpolate values along the Line of Best Fit. This will be reviewed in another lesson.