Here are some sites that will provide your students with a similar online testing environment to AzMERIT. These practice tests include writing, reading and math.
AzMERIT Practice Tests: http://azmeritportal.org/students-and-families/
Click on sample tests
Click on training tests and use the guest login
Florida Assessments http://fsassessments.org/students-and-families/practice-tests/
Click on take the computer-based practice tests