The Grade 10 students of Lakeview Integrated School tested the relationship between the brightness of a group of light bulbs to the number of batteries connected to it. In their first setup, they connected two identical light bulbs to two batteries. In their second setup, they connected two identical light bulbs to four batteries. In the last setup, they connected two identical light bulbs to six batteries. The batteries' brand and the specifications of the light bulbs used in all setups were kept constant. Their experiments showed that the brightness of the two bulbs increases as the number of batteries used as a power source also increases.​