In a traditional classroom of mixed ability levels, it is recommended that differentiation is the answer to helping all students achieve success (Heacox, 2012). This necessitates a shift from a "one size fits all" approach to one of greater emphasis on the individual in the learning process. While teachers seek ways to look at teaching, assessing, and learning through this different lens, the issue of successfully implementing differentiated instruction (DI) in the classroom continues to be challenging. This issue will be discussed with a focus on blending two major elements, backward design and formative assessment, as essential components in supporting and incorporating differentiated instruction in classrooms with mixed ability levels.