After the multiplication and division.. you need to make sure they understand fractions, add/subtract/multiply/divide fractions... also make sure he/she can do long division and multiplication...
After which you might want to make sure he/she can do word problems... it is really easy to teach a kid how to do the multiplication and division... but often it takes more time to get them to apply it. The word problems will help with that. I would make darned sure the word problem ability is there before moving on, sometimes people move kids too quickly because they can solve a problem.. but they forget that the kid also needs to know how to set up the problem from a description of the situation.
