Yes, the students definitely lose sight of the goal of this lab during the calculations. Actually obtaining the data was not difficult for most students and no one was struggling for time on data collection.
Many students were confused that "heat of" means q, and frequently forgot that q has units of joules. Also, make sure to check their calorimeter constant, since many first tries result in negative values, or they forget to divide q(cal) by delta T. They usually have a math error, not a procedural error.
For Part A, remind them to look at the big box on page 5-7, and if needed remind them of the relationship between density/volume/mass.
For Part B, if you tell your students to use the oven, be wary that the temperature of the Al will decrease if students are constantly opening/closing the door. This will muck up their Ccal if you wrote what the temperature is supposed to be (85) on the board.
For Part C, many students did not know where to start for the calculations, I pointed them in the direction of Eq. 5 on page 5-9 and that seemed to help.
One student finished the entire lab report, the rest took it home with them.