The thing is that you are using the tables for the WISC and they are NOT the same as for the WPPSI. As I explained above if I use those tables you used for my daughter I get a higher score than she actually has. I think for her the subtest total was 95 and for your son 96 (can't go back to check right now), and instead of the 144, she gets 140 (I think). that is why I gave the range above.