Here are a few math education jokes I heard recently. Two of them come from my Tai Chi teacher. I think they all contain a bit of wisdom as well as humor.
The teacher draws a right triangle on the board, labels the legs 3 and 4 and the hypotenuse x, and asks the student, “Can you find x?” The student rushes up to the board and pointing, says “Here it is!”
The teacher writes (a + b)2 on the board, and asks if anyone can expand it. A student comes up and writes
( a____+____b )2.
The teacher writes an equation on the board, and says “Suppose x is the solution to this equation” and starts to do some algebraic manipulation. A student waves his hand wildly. When the teacher calls on him, he says “But sir, suppose it isn’t?”