Flex has the ability to decide content that will be built into the assessment based on the material in that unit. It's dynamic functionality will remove skipped lesson questions so that the corresponding assessments do not contain material from that lesson. Similar to CRx enrollments, it will decide the content to be assigned based on the pooling of questions that were marked as incorrect on the pretest. While flex is a large factor with the CRx enrollments, it is not the sole purpose of it. If a custom course is created on the districts behalf by pulling content into the course based from the system, it will then build questions on the assessments that they had pulled. For example, if the same unit has content from a Science course built into it, as well as content from the subject of math is put into the same unit, it will end up having questions referring to both subjects on the unit test and the quiz that is immediately after that content in the unit.