1) From within your classroom, navigate to Math Settings.

2) Scroll to the Fact Fluency Settings and turn the setting ON. It is OFF by default.

3) All four operations will turn on. Disable the ones you do not want students to see negative numbers in.

4) If you want specific students NOT to have access to negative numbers, you can navigate to your roster, click the settings for the particular student, the learning tab, and adjust the settings.