My son recently took the OLSAT level A test and he was 6 years and 9 months old at the time of the test. He got a raw score of 53/60 and a SAI of 118. His score is based on age grouping and not grade grouping as per his school. I searched heavily to figure out how to calculate the SAI from his raw score but couldn't find any information.

Can anyone explain how the SAI is calculated and consequently how the percentile is calculated.

I am curious to see how many questions he should have gotten correct to have gotten above 90 percentile. He currently has a 87 percentile.