Just a reminder that his reported grade equivalents do not mean that he successfully completed items at that level of difficulty, only that his performance on the items administered to him was at the same level as that of the average student of that grade level on these same types of tasks. E.g., a second grade student scores at the eleventh grade grade equivalent. This means that she obtained the same universal scaled score on the second grade test that the average eleventh-grader would have obtained on the second grade test. The test itself may have included items only up into the fifth grade range. It is not the items at different grade levels that are being compared in a grade equivalent, but the performance of students in different grade levels on the same task, which may be well below the instructional level of one of them.

p. 39 of the document cited up-thread clearly states that +3 grade level items are not included in that particular STAR Math assessment. It may be that they have other versions that have higher ceilings. Alternatively, your child may have more frequent assessments, in which case the starting point will have been adjusted based on his prior assessments, which conceivably may make more items available to him, if the whole item set shifts upward. (Although the documentation I've read suggests that it will actually make fewer items available, if the grade-level item set is not shifted, possibly lowering his scores late in the school year.)



...pronounced like the long vowel and first letter of the alphabet...