If you cannot purchase a math work sheet because you think you may not have time to, then you can create on using your home computer and customize it for your kid. Doing this is easy. All you need is Microsoft word application in your computer to achieve this. Just open the word application in your computer and start a new document. Ensure that the new document you are about to create is based on a template. Then, ensure that your internet connection is on before you can search the term "math worksheet" from the internet. You will get templates of all kinds for your worksheet. Choose the one you want and then download.
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.