A stairway shows the parts of a slope in a direct way. The height or the "rise" and the length of the stairway, the "run," provide a graphic illustration of how a numeric designation for a slope is determined. A stairway 12 feet high and 15 feet long shows a slope of 12/15 or 4/5.
Use graphs to illustrate differences in slope. Plot a line based on a rise of 3 and a run of 2: 3,2; 6,4; 9, 6 and 12,8. Graph a second line based on a rise of 2 and a run of 3: 2,3; 4,6, 6,9 and 8,12. Point out the difference in the steepness of the slopes.
As the highway goes up or down a slope, signs indicating the grade alert drivers to the potential hazard. The grade's percentage, expressed as a fraction, defines the slope. Slope may go from lower to higher, or from higher to lower. A 10 percent grade sign warns that the road climbs or falls one mile for each 10 miles traveled. Use a piece of wood held at an angle and a toy truck to show how slope and speed correlate. Vary the angle for additional observations.
Use two rulers and several 1-inch high blocks to show differences in slope. Place the first ruler flat on the table. Place one end of the second ruler on the table alongside the first one and rest the other end on a single block for a slope of 1/12. Add a second block. Discuss how the slope's run, measured by the flat ruler, changes as the rise increases. Continue adding blocks and calculating the slope.
Use a common playground slide to demonstrate how slope changes the energy needed to move from one point to another. Measure the length of the slide's rise. Measure and mark off a similar distance on the ground. Take a pulse reading. Walk the measured distance on the ground and note the time required, number of steps needed and pulse reading at the end. Go to the lower end of the slide. Take a pulse reading. Walk up the slide to the top and note the time, steps and pulse rate. After a rest, climb the slide's ladder and take the readings again. Compare the three sets of numbers. Discuss any observations about difficulty or ease of each portion of the demonstration.