No matter what materials you choose, it is most important that you supervise your child constantly so that mistakes get caught rather than practiced. I learned this particular lesson the hard way. When my daughter was young, she did something that needed "attention." I no longer remember what it was that she did, but I told her to write the sentence "I will not disobey my parents again" 50 times. I should have known better, but I didn't check on her at the beginning and then I got busy. So, sometime later, she brought me 50 sentences of "I will not disobey my parents agen." She had just practiced misspelling "again" as "agen" __ 50 times! I'm not certain that we ever really got that fixed. This issue of NOT practicing mistakes is extremely important. Parents shouldn't give worksheets as busy work and teachers should only use them if you are going to have a non_math teacher substitute. White boards with supervision are always a better way to practice skills. If you need some time to do chores, your child will get much more benefit by helping you with the chores. And maybe you can work in a little discussion of numbers or counting while you do chores together.
Step 2: Work on the Skill _ Once he has met the skill, it is time for him to take baby steps on his and work on it. I will usually print off 5 sets of math worksheets on a topic. There are many great places to find these available. On the first worksheet, I let him work completely independently with no outside help at all. If he gets stuck, he gets stuck. We then go over everything together. I bought a piece of white board and eraser able marker; I show him how I would do the problem on this board. It makes it easy for him to see. How we do the second and third sheet depends on his success of the first page. If he did well, I let him work on those by himself. If he struggled, he will do all problems on the white board. The fourth sheet he does totally independently. We review that sheet and save the last math worksheet to be done a day after we complete this process, as a review.