You say that as if there's a limited amount of math to be taught. [Which he finds funny since knowledge seems to be the only limitless thing available in the prison now. Or maybe that's sad?]
I thought that, today, I would give you logic problems. Nothing new, only new ways to apply the reasoning abilities that you have already. Problems like this--somewhat practical ones--seem to appeal to you more than abstract mathematics.
[He pushes a worksheet and a pen Nico's way with a smile. The problems are along these lines, for the most part. There's usually more to lessons than this, but Chekov has been impressed with Nico's overall grasp of the concepts they've covered and wants to see how he does with this.
He'll work on his own things while Nico contemplates the assignment, ready to answer questions or go over solutions.]