Based on my 5th grader's experience in compacted math, I'm thinking the first half (3 units) of the 5th grade curriculum? That would be factors and multiples; geometry; and fractions, decimals, and percents.
http://www.montgomeryschoolsmd.org/curriculum/math/elementary/grade5/
FWIW, it's not like the teachers have been telling us when they moved from 4th grade math to 5th grade math. I know his class is working on absolute value right now. Curriculum guides suggest that that is usually covered midway through the 2nd marking period of 6th grade.