These days, kids have so many enjoyable ways they can work on mastering their facts. Flash cards have been converted into computer games that can provide not only needed repetition of the same facts, but timers to encourage automaticity (a fancy new education word for answering by reflex, rather than thinking about it, or counting on our fingers). I have included several of my favorites on my Links page, but there are so many out there that can be used to teach or to test mastery of the facts. There are apps for your iPhone, games for the kids' DS or other hand-held devices, multiplication rap songs to appeal to auditory learners, computer software games, and countless on-line activities.
Still, all the facts cannot be mastered overnight. Most kids need guidance in pacing themselves in working on the facts. Most teachers recommend working on one facts set at a time, with reviews built in for previous fact sets. I have seen other approaches on educational instruction web-sites, but haven't tried their strategies. In class, I like to use a combination of both the old-school, and the new technological approaches, but I always try to add some twist of competition with others or with one's self as a motivator that appeals to most kids.
I have known few kids who can master their facts without time and consistent practice. One of my own children learned them easily without my help, and the other needed to work with me every night until they were mastered. As you probably know, this is one of the most important math skills your child will undertake, and one that will be used throughout life, so take the time to make sure your child gets them. Work on a particular fact set in the car each time you go somewhere. Play games with them using playing cards, the computer, or inexpensive flash cards that can be purchased at the dollar store. Consistency is more important than total time spent. Don't try to work with your child for three hours the night before the timed test, but work with them 5 or 10 minutes every day leading up to the test, and you will see better results.
I will do my part at school, but children whose parents get involved in the process tend to learn them more easily and maintain them over time better.