Percents are ratios that are equivalent to a comparison of a "part" to a "whole" and are based on 100 as the denominator.[br][*]Move the slider on the [i]x[/i]-axis for the value of the value to be marked up or marked down.[br][*]Move the red percent slider up or down for the percent value (expressed as a decimal).[br][br]First move the slider on the [i]x[/i]-axis to determine the original number to be marked up or marked down. To find the actual amount of mark up, move the percent slider to the percent [i]after[/i] the mark up (e.g., 25% mark up = 125%). Similarly, to find the actual amount marked down, move the percent slider the value [i]after[/i] the mark down (e.g., 25% mark down = 75%).[br][br]Conversely, to find the percent of mark up or discount based on actual amounts increased or decreased, first move the slider on the [i]x[/i]-axis to the original number to be marked up or marked down. Then move the red percent slider so that the desired amount of mark up or discount is displayed in the [i]y[/i]-coordinate for points A and B.

[list][br][*]How is the amount of mark up or mark down affected by changing the original amount?[br][br][*]How is the amount of mark up or mark down affected by the percent of mark up or mark down?[br][br][*]Is the amount of mark up the same as the percent of mark up? Why or why not?[br][/list]