division
this is a hard concept for kids--they get really overwhelmed with it and scared by the "big" numbers.
1. does he have the process down--divide, multiply, subtract, check/compare, bring down? (Or...Does Mcdonalds Serve CheeseBurgers?)
2. help him estimate with rounding---he is probably stymied because he doesn't know his 54 or 32 or 77 times tables! (me either!) but if he realizes that all he has to do is get a good guess started (and he doesn't have to do 54 x 3, nope that doesn't work 54 x 8, nope that doesn't work.....). if he says, hey, 54 is close to 50--i can count by fifties or do some mental math multiplication with 5 and i see that only 4 50's go into that number. therefore, only 5 54's should go in there. (now, depending on the number, that might actually be high or low---but he's know for certain once he multiplies 54 x 5 if the actual answer is 4 or 6 and no more guessing.
3. what usually works for getting this concept down is repetition, repetition, repetition....practice, practice, practice.
good luck!