When I had to tutor a 5th grade student in division, I noticed she had a lot of trouble with her adding and subtracting. She knew her multiplication pretty well.But I basically had to start her from the beginning that way she could do her division just as good as she did multiplication. After two weeks she had addition, subtraction and multiplication very well. After each lesson I would give her quizzes and by the end of the second week she finally got 100% on her adding and subtracting. Division took a little bit linger because she kept forgetting about bringing down numbers and where to place the numbers. I was very proud that after a few weeks she knew where numbers were supposed to go and what to do with the remainders. She still had trouble once in a while when it came to placing numbers, but as soon as I was about to say something she would catch it faster.