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.
The most important thing about these math worksheets is that they are used for tutoring and not for the main course studies. That is why they are used by tutors to offer remedial tuition and by parents at home so that they can offer their kids extra tuition to sharpen their skills. Math is known to be difficult and is often a headache for the young and so the math worksheets come in handy in helping resolve this problem. Thanks to the sites over the internet that offer free printable math worksheets, you do not need to worry about the cost of purchasing one, maybe only the ink cost. So don't go making excuses for not being able to access a math work sheet.