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.
Have you ever noticed how many K┨ math content websites are devoted to math worksheets? There seems to be an increase in websites that cater to desperate teachers and parents by offering fast, free "worksheet generation", free fractions worksheets," etc. Now, as a former teacher I am not saying that one should never use math worksheets; however, I do believe that many teachers are using a very superficial method of instruction that relies too much on low_level math worksheets and hands_off instructional approaches. Worksheet lessons move from reading the directions aloud, to doing sample problems as a group, to completing the worksheet independently (or at home with parents), day in and day out. Teaching needs to be more than passing out worksheets. Whether you are the classroom teacher, instructional specialist, or parent, the methods you use greatly impact the level of understanding achieved by your students.