Learning of new concepts being impeded by an error in previous work
There is a difference between being wrong and knowing you're wrong.

I like to think of this with the analogy of Wiley the Coyote from looney toons. He would usually try to catch the runner, and run off the cliff, but keep running for a while, and only fall when he realizes that he ran off a cliff.



The point in which your student is doing the assignments based on incorrect previous calculations is that point between coyote running off the cliff and realizing he has done so.

I'm not sure of the terminology about this phenomena, but here's my theory on why people tend to do this:
Most of the students nowadays are conditioned to feel right about everything because knowing, that you are wrong feels bad, they feel like there is something wrong with them (rather then just being wrong), while the alternative, of being wrong and not knowing about it that feels exactly as being right.

This conditioning is introduced in our educational system very early and often results in not taking chances that could result in them being wrong, or (more related) in not even considering the possibility that they might be wrong at some point (when most of the time they are).

I think that the only way of fixing this is deconditioning ourselves (or your students) in this case, that being wrong is something bad. Instead, indicating being wrong as a sign of progress. I think Einstein said:

A person who never made a mistake never tried anything new.


Encouraging your students questioning even things that might be established as truth by others is the key in my opinion.