What age level is FLEX Curriculum best suited for?

FLEX Curriculum is suitable for kindergarten through 12th-grade students and doesn't pigeonhole lessons into specific grade levels. Instead, lessons are categorized as beginner (geared toward K-5), intermediate (geared toward 6-8), and advanced (geared toward 9-12). However, teachers are welcome and able to scale lessons up or down to meet the needs of their unique students. Furthermore, all lessons are aligned to the National Core Arts Standards and selected state standards.