When he runs into a tough problem, he often goes to his teacher for advice.
Tips
register
Polite and a touch formal, used when sincerely asking someone with more expertise. The pattern is 向 X 求教 ('seek instruction from X'). Often paired with 不耻下问 ('not ashamed to ask those below you') as a praise phrase.
memory
求 ('to seek') + 教 ('to teach'), literally 'seek teaching'. The 教 here is jiào (teaching) not jiāo (to teach), the same reading as in 教师 ('teacher').