This object lesson requires a magnifying glass, a sunny day , a piece of paper, and just a regular piece of glass. Take your class or family outside and give one person the magnifying glass and another person the normal glass. See who can burn a hole in the paper. The lesson could take many directions after this:
In order to get quickly to the heart of a problem with a solution, you have to have concentrated effort, or,
Magnifying your calling means giving real concentration and the result is magnified power, or,
look what unusual powers glass can have when it is concentrated in that one spot. That is what can happen when a group works together to solve a problem. If they are all working together. If its not a concentrated effort, then there is no power, etc.