The same children can play the games but in different ways, since the programs are tailored toward the learning styles of each child. This is what makes adaptive learning an essential tool in classrooms as well.
Do choose worksheets that are appropriate for the child's level, since children can get discouraged easily, if they are unable to perform the activity. Well illustrated worksheets with cartoons are also more likely to appeal to children. Worksheets that use common situations children come across at home, school, in the market place etc and that use common objects known to children would be more relevant.
If your third grader needs help with math, there are many useful tools that can downloaded directly from the computer. Math is a subject that is best taught with visual aids, making the lessons more tangible for students.
Worksheets also, when used properly, provide both the students and parent / tutor immediate feedback as to the child's progress. This means they can be used to point out areas where the student needs further reinforcement.