My 7 years old DS is taking classes with both 2nd-grade and 8th-grade. He recently took PSAT 8/9. He scored 97th percentile overall, 99th percentile math and 63rd percentile EBRW. This is higher than the 5th grader Davidson Young Scholar test requirement. However, his grade level is 2nd or 8th, which is not within the 3rd to 6th-grade PSAT requirement range. He won't be allowed to use this test result to apply for the young schor program.
The test requirements only care about the grade level, no the age.