"On a bad day, I have no ideas. On a good day, I have a lot of wrong ideas. At least with wrong ideas, I can mix them together and come up with a right answer."
That's the idea behind this number puzzle, which I've intentionally designed to be really tricky and frustrating (at least, it was for the 3rd through 6th graders I tried it on.) The relationship between the three columns appear to be arbitrary, but there actually is some method to the madness: the students should be encouraged to come up with lots of "wrong" answers that may work for one row or maybe even two, or maybe search for patterns that are not there, and then, as they work. The point is to brainstorm wrong ideas, and then use them to come up with a "right" idea.
I've provided this in lots of formats: full page b & w, color, ganged up 4 to a page, as well as teaching tips, solutions and even a "Do It Yourself" set of pages so your students can make up their own number puzzles and share them with one another.
Two amazing puzzles, multiple formats, detailed solutions!
Another great product from SamizdatMath!