Are you using Engage NY or Eureka math? Here are some great quizzes for you. I have written the Topic quizzes for 8th grade Module 3. There are 3 quizzes, one for each topic A to C. These are aligned to SBAC and use the Smarter Balanced Item Specs.
You will get great data and information about which of your kids need a little more help in learning about similarity, dilations, and The Pythagorean Theorem.
The file is a Word document and you are free to edit and make necessary changes to teach your precious children. You could also make multiple versions for yourself if you wish.
These are great as formative assessments. I have created the images to look just like the SBAC test.
Happy Math, Megan
Note: I had a very difficult time matching up the content of Topic B to the item specs.