My son had almost the same WJ-III broad math score at the end of 1st grade. His age equivalent score was 10-1 (10 years 1 month), meaning that his raw score was the same as a 10 year old at the 50th percentile. A 10 year old at the 50th percentile has *not* mastered 4th grade math. At the time my son took the test, he had just finished Primary Mathematics 2B, and I would say that he had mastered 2nd grade material but no more.