Why do they start at the beginning? Is it because "it is a very good place to start," or is it because that is how they have been trained?
The way most assignments are structured, the items get harder the farther in you get. I understand that this progression can provide support to students as they build on prior success, but I do not think they see it that way. Ask them and I believe you will find that they do it in order because the assignment implicitly suggests that they do it in order. They have been disempowered to make meaningful choices about what items to try.
What if instead we asked the students to look over the items and identify those that they might need peer or teacher support on? These are the items the students could work on during the closing minutes while they have support available. They can finish the easier problems on their own. Dare I say it? We could flip the assignment.
This could also serve as an assessment for the teacher. Knowing which items students considered challenging could offer insight into the effectiveness of the lesson or inform future instruction.
A change like this represents one of the subtle shifts we encourage teachers to make in their practice. We do not always need to make big moves to offer students a chance to make choices and, therefore, take more responsibility for their learning. A slight change can increase the likelihood of student engagement without requiring a lot of extra planning or preparation. This is another example of educational sustainability for both teacher and learner.