So, the answer is nuanced:
* If you're struggling with basic multiplication facts: Yes, you should definitely be working on mastering them. Middle school math builds upon this foundation, and struggling with multiplication will make algebra, geometry, and beyond much harder.
* If you know your times tables but make occasional mistakes or are slow: Regular practice and reinforcement are beneficial. Speed and accuracy are important, but perfection isn't necessarily required. Focus on the areas where you struggle.
* If you're already fluent and quick: You probably don't need dedicated multiplication table practice. Your focus should be on applying your knowledge to more advanced concepts.
In short, it's not about *age*, but about *mastery*. If you haven't achieved fluency and accuracy, middle school is a perfectly acceptable time to solidify those skills. If you have, then your energy should be directed elsewhere.