My 10 yr old son has never had an IQ test so I don't know about PSI but I think my kid with motor dyspraxia and lower than average visual motor integration ability might not do as well on this if it requires good fine motor skills and speed.
I thought my son might be gifted in math when he was doing some multiplication in kindergarten and was doing math with negative numbers right before he turned 5 and he came up with his own way of doing subtraction that didn't involve regrouping, like 24-17 he would say 4-7 is a negative 3 and 20-10 is 10 and -3 and 10 is 7. When he took the WIAT the month he turned 7 it appeared that he was grade levels ahead of where he should have been even though all he did for math was play online games and he had read a math dictionary. We had only used a Singapore math workbook before the test and I think it was 2A or 2B but I don't think it covered anything at the 4th grade level so I didn't know how he scored at a 4th grade level on the test. The educational psychologist who tested him said he refused to use scratch paper and would only do mental math. He said he thought if he had used scratch paper he might have tested even higher.
But my son never wanted to practice math. He said math was useful but he didn't particularly like it. He didn't know why anyone would want to do math when there is much more interesting science and history and vocabulary to learn. When I could get him to do math I had to be his scribe if I wanted him to do more than 2 or 3 problems. His handwriting issues caused trouble with long division and multi-digit multiplication and sometimes his 2's looked like 5's and his 9's were backwards. I think a lot of his frustration with math had to do with these handwriting issues, but I only rarely let him use a calculator.
I didn't let him use a calculator because I was afraid he would stop working on number writing. At 8 I told him he would have to do his own writing and if he wrote a number backwards or if his 0 looked like it might possibly be a six, he practiced writing that number. He absolutely hated math for a while, but his number writing and ability to keep columns straight is getting better and he got in the habit of looking at his answer and making sure it looked right. We sometimes battled over the way he found the answers. He could come up with answers with less writing than I did. Like when he solves percent problems using easy algebra equations he says he can see the problem in his head and doesn't need to write it out. I did start letting him use a calculator for some things. If I let him use the calculator he seems to like math a lot more.
Since he always liked to do a lot of mental math instead of writing, he uses aaamath.com to practice things like converting fractions to mixed numbers quickly. Since there is a clock on it he can easily see if he is increasing his speed.
