This Demonstration generates the horizontal sum of two consumers’ demand curves (gray) to generate a market demand curve (black). As you increases the number of consumers, the market demand curve changes accordingly. As you see, a nonlinear market demand curve can be generated from simple linear demand curves of individual consumers. Select the “show quantity demanded” button to see how the market demand is generated mathematically. It is a horizontal sum of all the individual demands in the market. The framed numbers show the individual quantities demanded and the sum of them is the market quantity demanded.