If you do want to produce your own worksheets and don't have the Microsoft software, you can download free tools like OpenOffice or use an online word processor or spreadsheet such as the free Google Docs which help you do similar tasks. You just need to create a table with as many rows and columns as you need and then type in some numbers before printing it off for your children to practice _ depending on the level of complexity choose single digits or multiple digits. If you're not sure what level to start at, aim low, start with easy numbers and see how your child goes, the self_esteem boost they'll get from acing the first worksheet will give them confidence for more difficult math problems.
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.