This is a task from Illustrative Mathematics. The students constructed an argument that described how they found equivalent fractions. The directions for this task were slightly modified for my fifth grade students. My fifth grade students we asked to come up with no more than six equivalent fractions for each of the diagrams on part b. Beyond what is already stated this task also met CSSSM:CCSS.MATH.CONTENT.4.NF.A.1:
Explain why a fraction a/b is equivalent to a fraction (n × a)/(n × b)
by using visual fraction models, with attention to how the number and
size of the parts differ even though the two fractions themselves are
the same size. Use this principle to recognize and generate equivalent
fractions.
Microsoft Word version: 5_NF_Fractions_Problem_Construct_IllustrativeMathematics
PDF version: 5_NF_Fractions_Problem_Construct_IllustrativeMathematics