A "Whoa!" problem is one that makes you say, "Whoa!" after you read it. It usually has many steps and at first, you might not even know where to start.
I made a video for my students to watch today. It's a wee bit long and at times, the camera is more shakey than I'd like it to be, but it gets the job done in helping students understand how these problems are broken down into small, manageable steps.
Also emphasized in the video is the most important step of all: rechecking your work!
After watching the video, we also discussed the importance of asking yourself, "Does my answer make sense?" It's one thing to have done the addition/subtraction/scale correctly, but if the answer itself doesn't make sense, you'll need to go back and recheck your strategies and/or choice of operation.
We're going to watch the video again in class this week and then solve our own Whoa! problem by breaking it down into small chunks, rechecking our work and then asking, "Does this make sense?"