After writing a less than favorable review of a math drill program, I thought it would be helpful to share some of the drills that my family does enjoy.
Our absolute favorite is Khan Academy. Khan Academy is completely free and completely amazing. It covers many subjects, but we've only used it for math so far. It includes a great drill section that let's you start at the basics of addition and work your way down a "tree" to more complicated material.
In addition to the drill practice, Khan Academy also offers free video tutorials that really help explain concepts from the most basic of addition to linear algebra. My boys BEG to visit Khan Academy. No flashy lights, no annoying sound effects, no advertising. Students can log in under individual accounts so that you can track their progress. It is very simple to follow. Easy and impressive. I would be willing to pay quite a bit for access to this website, but it's completely free.
Sheppard Software has fun math games for Kindergarten through 6th grade. The games have an almost arcade game feel to them. There are some ads on the pages, but nothing too obnoxious. It's free and fun and makes a nice "reward" for finishing math lessons, even though it's a math lesson in itself.
IXL Math is another site offering games for Pre-K through Algebra. There are no ads and it's design is very tasteful. You cannot save progress unless you become a member. There are other perks, but membership is not free. We just enjoy the free games and forget tracking progress.
Math-U-See has a great drill page. No frills, down-to-business. Teachers can choose which facts or skills are drilled. If you have something specific that you know your student is struggling with, this is especially helpful.
Math Drills Homepage is another with some interesting drill subjects. It covers the basics as well as more complicated topics, like loan amortization. The sound effects are annoying (applause for every correct answer, buzzer for mistakes,) so be sure to turn down the volume.
These are all online drill lessons. For a more lasting reinforcement, I have some great (free) resources to share tomorrow.