Which of the following words is different from the others?

The word "Calculator" stands apart from the others because it refers to a tool primarily used for mathematical calculations, rather than a mode of transportation. The other options—Helicopter, Bicycle, and Car—are all forms of vehicles that facilitate movement from one place to another. While Helicopter and Car are motorized transportation methods, Bicycle is a non-motorized vehicle. This distinction in functionality makes "Calculator" the outlier in this group, as it does not serve the purpose of transport but rather that of computation.