This self checking worksheet features summation notation formulas of k, k^2 and k^3 with limits thrown in to keep the students on their toes. My students love worksheets. They would rather do a worksheet than book work. It must be the child in them coming out of my 18 year olds. I think they like the riddles the best. If one student finishes first and starts to read the solution to the riddle out loud, the other students 'shush' them. It always makes me laugh.