This self-checking worksheet offers a review of adding, subtracting, multiplying and dividing imaginary numbers. It also makes the student work with negative radicals which are perfect squares, such as sq root -9 = 3i. Also on this worksheet is one problem of i^82 and one problem which asks the student to find the range if values of x which makes the radical complex. Once the problems are worked out, the solutions will reveal the answer to a riddle.