Each fill in the blank has specific instructions above the question. If the instructions don't address your issue, you probably have the wrong answer. Follow these steps on Page 2 of the Practice Set Instructions.
Important: Students should not stop during a Practice Set to ask a parent or Dr. Shormann a question. This uses valuable time that should be used to practice solving math problems. It is much more efficient and effective to skip the question, answer all the other questions they can, submit it, and follow the steps on Page 2 of the Practice Set Instructions.