Riddle worksheets are available in books and online. BogglesWorldESL.com has anagram riddle, homophone riddle, rhyming riddle, and many other type of riddle worksheets available for free. KidsLearningStation.com provides free riddle worksheets with word and picture clues for younger students. TeachersCorner.net provides more difficult riddles geared towards older students.
Math riddle worksheets available include those that have a numerical answer and those that make students correctly answer math questions in order to get the clues or answers to the riddle. SuperTeacherWorksheets.com has both types of math and English riddle worksheets available with a subscription. Math-Salamanders.org provides both types of math riddle worksheets at no charge.