Timed drills for math facts?

Are timed math tests (drills) necessary and for what purpose? If necessary, how often should facts be tested? Are timed math tests recommended for students who have "math issues." , such as low confidence and slower progress.

I simply feel that timed drills are a tool among many, when it comes to learning math facts. Some kids will "thrive" on them, or in other words quickly learn when they are used. Perhaps they like racing against the clock or like the challenge. There exist computer games that are timed that can work very well for drilling facts. Check for example:

Math Magician games has a simple 2-minute countdown, and if you answer 20 questions in that time, you get an award.

Some of the games at Sheppard Software don't time you but give you more points the faster you go. That site is actually filled with several types of games just for math facts practice.

Yet for other kids timed drills may be counterproductive and end up in tears and frustration. The proof is in the pudding though. Just try them and see how it goes.

I feel timed drills are a good tool but not absolutely necessary. Kids can learn their facts so many ways. For example, some learn to use clever shortcuts such as "Since 7 + 7 = 14, then 7 + 8 is one more or 15" and actually perform that in their heads so quickly that you can't tell the difference if they memorized it or did some calculation. Some learn them by heart from much usage in problems, without being timed.

You're welcome to use timed drills with low-confidence students because you never know, perhaps a student like that has decent memory and can succeed with it. However, if you already know that a student cannot easily remember facts without context, then it might not work.