I really think one of the hardest part of long division is going to be the subtraction piece. Students have lapsed in their skills of regrouping (borrowing) when the numeral in the "bottom" digit is larger than the numeral in the "top" digit. It has taken some reminding to get them back on track, but hopefully they will remember their skills with some practice. I like to use division as the time to review subtraction, rather than cover subtraction in a separate review unit. That being said, it can be frustrating to be this far along in the year and remember that students are still deficient in this basic area.
Parenthetically, Motion Math, by the way, has some excellent applications that may be downloaded to your iPhone, iPad, and similar devices. If you are interested, I have also enjoyed looking at a free app named Math-Sprint (with a dash) which is also available in the app store. If you don't have one of these devices, simply make up some problems like the ones shown in this post, and continue to work with your child on the skills involved in correctly solving the problems. It will certainly make school life easier - for student and for teacher.