The purpose of this activity is to remind students of their work in grade 3 using number lines as a way to reason about fractions. Students see that they can partition number lines in a similar way as they partitioned fraction strips and diagrams.
This activity gives students another opportunity to notice the relationship between two fractions where one denominator is a multiple or a factor of the other, and then use this relationship to locate fractions on a number line. In doing so, students practice looking for and making use of structure (MP7).
The work prepares students to use number lines to think about equivalent fractions in the next lesson.