DS7 was tested at age 6 and sounds similar. Very strong in math, but reading as well. His PRI was 141 and VCI was 114. I wonder if the fact that your DS is a quieter kid has something to do with the lower VCI score, as I think this affected my DS's score. He tends to give very brief answers to questions, have anxiety if put on the spot, or say "I don't know" unless he's very interested in the question.

He had a 19 in Picture Concepts though, and Matrix Reasoning was 18.