A good way to help your kids to understand how to solve word problems is to have them write their own. Often they see word problems as tricky before they even read them. By having them make their own, they will realize that there really is just one right answer and that it isn't impossible to figure out. After doing this several times, they will help themselves to understand what pieces of information are necessary and they will better understand how to figure out what exactly the problem is asking. They should also begin to have a general estimate of the answer before even beginning to solve the problem.