Visit Web sites that offer IQ tests for children four years of age. For example, tests are available at "Expert Rating" and "Dr. Phil." You can also purchase a book such as "I.Q. Tests for Children" by Martin Lutterjohann or a comparable book that allows you to test your child's IQ at home.
Give your child a practice IQ test that you walk through together. Show your child how to interpret the question, what the various question formats look like and how to select an answer.
Explain to your child that you would like him to practice this activity again, but this time on his own in a quiet working environment, such as the kitchen table or a small desk. Tell your child the number of questions he needs to answer in this activity and how long he has to do it. Place a large clock in front of him, and tell him that he needs to finish at a specific time. Explain to your child that you want him to do his best on his own.
Go to the opposite end of the room and allow your child to work uninterrupted. When he has completed the test, score his answers according to the scoring chart provided.