All children develop as individuals. Parents and caregivers should use the age ratings below as a general guideline, taking the abilities, temperament and interests of their children into account.
Tracing activities develop a child's control of the small muscles of the hands (fine motor skills) improving hand/eye coordination. Learning shapes and colors allows children to group or classify items -- children develop their ability to make logical connections -- a precursor to both math and language arts.
If an aspect of a project is frustrating to the child, provide assistance - try to keep things fun. Sing songs, read stories or watch shows with a similar theme as the worksheet you choose to supplement the project - again focusing on extra activities that the child enjoys to help keep them motivated.
Take breaks, when necessary. Choose a time of day when you and the child are relaxed. Provide rewards (verbal encouragement, gold stars on "chore chart" checklists or awards for tasks that have been mastered) and change up the rewards when needed. Don't underestimate the "reward value" of one-on-one time with a loved grown up! Ten minutes of "homework time" with daddy after work can become a special ritual for both father and child (at least it did for our family *grin*).
Visit DLTK's Shapes Buddies for printable crafts, coloring pages, games and poems to supplement these shape recognition worksheets.