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.
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.