It may be best to take the course you place into. However, you can choose to review and retest to try to obtain a higher score.

Once you have taken the ALEKS PPL test, you have access to a learning module for a limited amount of time that can be used to review before retesting. Incoming students can access the learning module through the Next Steps Center.  Current students can contact the Math Placement office to find out if their learning module access is still available.   You can access the learning module within 12 months of your first attempt at the ALEKS PPL test.  

Other free review material is available here.

There is a 24 hour waiting period between ALEKS tests.