a student our age

English as a Second Language English Vocabulary, Grammar and Idioms
1
  1. How did you study when you were a student our age?
  2. How did you study when you were a student of our age?
  3. How did you study when you were our age?
  4. How did you study when you were at our age?
    Please correct the above questions.
    Thanks.
2

1, 2 and 3 are correct. 3 is the most natural.