You can always customize the curriculum for each student individually after the students took the Placement test. 

In your teacher account, go to the Reports section and select Weekly Dashboard to view the list of your students. Click on a certain student to see their current progress and assignment details.

By switching to "Manage Curriculum" you will be able to customize the number of lessons assigned to this particular student by selecting the necessary modules or topics from the Happy Numbers curriculum. Tick off modules or topics you don't need and add the necessary ones.

Since Happy Numbers was developed as a coherent PK-5 math story, students will repeat every particular skill many times during the learning process. That's why we don't recommend assigning the topics which are already done, even if a student doesn't show good accuracy. Any skill will be repeated, and in case of the mistake we will provide immediate feedback and repeat the skill step by step if needed.