Mrs. Ross' class consist of 4th and 5th grade resource students. She teaches 4th and 5th grade ELA in the afternoon together. Her students are on a 1st to 2nd grade reading level. Mrs. Ross incorporates both sets of standards when teaching, but because the standards build on each other she leans more toward the fourth grade standard to give her students a stronger foundation. When it comes to unit testing, Mrs. Ross feels that both sets of students would benefit from taking the fourth grade assessment, and only assessing the 5th grade students on the standards that 4th grade does not address. What should Mrs. Ross do?