Increase in Quantity Demanded:
When consumption of a commodity increases as a result of a fall in the own price of the commodity it is described as increase in quantity demanded. It is shown as a downward movement along the same demand curve.
Figure: Increase in Quantity Demanded
From Figure when the price of the commodity was c5,000, quantity demanded was 40 bags, and, when price fell to c4,000 consumption increases to 60 bags.