Happens to the best of us, but I didn't realize what happened until after it was too late. Part of the problem is this assignment was given on a day I was out so I wanted the least friction possible. Compounding the problem is I was out the next day as well and the material was going to be on a test I left for them. But lesson learned. Here's what happened.
We were covering angular and linear speed in Pre-Cal. My student teacher had given the intro last week, the kids struggled initially but were doing it ok with it. Enough that I felt comfortable testing them over it. I left this assignment as a summary activity and to make sure they had a feel for the kinks (converting things like pi*in/min into mph mostly):
I liked the planetary problems I came up with. But can you see how I screwed them up? I told them everything! The process I went through to search for things like "radius of Earth" "6378.1 km to mi" "diameter of a size 5 soccer ball" were things THEY should've done instead. Even telling them how a 24 hour spin translates to rotations per hour was terrible.
So, blah. File this as "must fix" for next year. And try not to do this as we continue forward.