Cases of word usage

1) the science of numbers; working with numbers (arithmetic)

2) to find out (something) by working with numbers (calculate)

3) a person working with another or others (colleague)

4) the willingness shown by, an act of, working or acting together for a common purpose (cooperation)

5) all the people working a boat, ship or plane; all these except the officers (crew)

6) the artificial process of removing waste products from the blood, e.g. when the kidneys are not working (dialysis)

7) working in elections, e.g. by canvassing, making speeches (electioneering)

8) (of machinery) able to be in a safe state if it stops working (failsafe)

9) a number of workmen or prisoner working together; a group of criminals (gang)

10) a set of toothed wheels working together in a machine, e.g. to connect the engine of a vehicle with the road wheels (gear)