put your thinking cap on
put (one's) thinking cap on
To begin thinking very hard about something, especially a solution to a problem. If we all put our thinking caps on, I'm sure we can come up with a way to earn enough money to go to the baseball game this weekend. A: "Well, boss, what do you think we should do?" B: "Just let me put my thinking cap on for a minute."
put your thinking cap onor
get your thinking cap on
If you put your thinking cap on or get your thinking cap on, you try hard to solve a problem by thinking about it. We need to put our thinking caps on and decide what can be done to prevent the problem. We've got five pairs of boots to give away, so get your thinking caps on and answer the following questions. Note: This expression may refer to the cap which judges used to wear when passing sentence or judgment.