Mathspace has a powerful Math Engine that checks for each step in a student's working, rather than just the final answer. This can get tricky, because there is often more than one way to approach questions, especially at higher levels.
In general, Mathspace will accept mathematically valid and correct steps - so even if a student approaches a question in a way that our content authors haven't thought of, it will still be marked as a correct step. See below for an example of different approaches to a question - some more obscure than others.
If a student skips to a final answer, it will be marked correctly unless intermediate steps are essential to the answer (e.g. proofs). In general, we encourage students to enter in intermediate steps, but do not enforce it.
If your students encounter a question where they have put in a valid step, and Mathspace has marked it incorrectly, be sure to have them let us know by submitting feedback.