put thinking cap on

put one's thinking cap on

Fig. to start thinking in a serious manner. (Usually used with children.) It's time to put our thinking caps on, children. All right now, let's put on our thinking caps and do some arithmetic.
See also: cap, on, put, thinking

put your thinking cap on

to start to think seriously about how to solve a problem Let me put my thinking cap on and see if I can come up with an answer.
See also: cap, on, put, thinking