Is it possible to put the problem number on the page with each problem? I find that even though I try to keep track of the problem numbers, I get so engrossed in solving them that I lose track of what number I'm on then when I can't figure out the solution to one I'm not sure which one I missed. Even if it said "you solved problem 4 correctly" or "sorry, you failed to solve problem 7" would be helpful. Thanks.