The actual statement from the book (p239-240) includes the part in bold.
"When a fifth grader receives a tenth-grade equivalency score, it means that the child is ready for the same curriculum as a typical tenth-grade student-not an advanced tenth-grade student."
If the typical 5th grader is eleven and the average 10th grader is sixteen, it seems absolutely plausible that the gifted eleven year old can do the same work expected of an
average sixteen year old at an average school.
IMO, the average 10th grade curriculum would make an excellent 5th grade �honors� curriculum similar to when high school students take average college level courses as honors and AP/IB classes while in high school.
Regarding grade or age equivalencies, my son had both young and older adult age equivalencies on his SB-5. I wouldn�t know whether the twenty-something or fifty-something score would be considered more advanced. They certainly struck me as meaningless.
