Are the problems too close together? Make sure you can distinguish between the problem number and the actual problems. The problem numbers should be less obtrusive. Students with and without ADD and ADHD can become distracted by too many distractions!?
Teachers, who are adept in the subject, rack their brains and generate new worksheets with a support answer key to guide the instructor. There is no limit to the number of worksheets you generate for the class or tutorials and they can be used for distribution purposes.