Learning times tables is a great opportunity to teach kids about goals. Make and print your own worksheets, time and track progress. See Math Fast Facts Challenge for free time test builders and description on how we practice in our class.
Math Facts is 95% rote memory that kids need to just memorize here some of our class's favorite Fast Facts Tips & Tricks.
Bottom line is practice, practice, practice. Make it a daily habit, 15 minutes on the kitchen table every day for 1-3 months now will establish a strong math foundation for the rest of their life.
There a lot of great workbooks to help with the practice, here are some of mine.