Multiplication worksheets are a quick and easy way to introduce some math revision at home. At first your kids may not appreciate being given extra "homework", but the advantages they will gain from "sharpening the saw" and practicing their math will serve them well; both back in the classroom and on in to later life. With a basic knowledge of Microsoft Excel or Word you can easily make your own math worksheets, but not everyone has that knowledge so it's fortunate that there are many websites dedicated to providing free printable resources, usually in PDF format. You just download, and print _ the only software required is the free Adobe PDF reader.
I teach the upper grades in my school, yet I continue to see kids who do not even have basic algebra skills in place. As a parent, I'm very aware of what my own children are learning in school. For the most part, I've been happy with their progress, but as they rise in grade level, I'm starting to see more emphasis on a loose understanding of the concepts and less emphasis on skills__particularly skills with arithmetic of fractions. The main problem with what I see with my students and my own children is that kids are taught "concepts" and are not taught skills__unless they're lucky enough to have a teacher who knows better. Most particularly, children are not taught mastery of arithmetic with fractions. Unfortunately, virtually all of their future math education depends on being able to do fractional arithmetic.