Cathy,
Perhaps you could have your son bring a book that he enjoys which demonstrates his highest reading ability.

When my son went for his assessment for early entrance to 1st grade, he brought a globe. It served as an ice breaker. The assistant principle asked him to find different states and countries. She told him that she had lived in Turkey and was quite surprised when he immediately pointed it out. He then proceeded to identify all of the nearby �stans�.