I believe in growth mindset - the idea that you can get better at things by working at them. It can be a hard thing to live at times - we all seem to have certain places where we have blinders about our ability to improve (or our students' ability to improve!)
With that in mind, I have been working on my mental math abilities. I've been playing a game where I keep track of changing numbers by adding and subtracting. The numbers are pretty small - usually less than 10, though not always, but the running total can grow fairly large.
I am sure that it's good for my brain to play this game, that I'm improving my ability to do mental math.
Here's what I wonder, though: does it matter if I get the right answer? I have discovered at times that as I keep track of the running total, I have made computational errors - not particularly surprising, since it isn't something I'm particularly stellar at. My sense is that it's the activity of trying the math rather than getting the right answer that's important, especially since I doubt that I'm reinforcing bad math by occasionally adding numbers incorrectly. However, I can believe it would be a problem to form neural pathways to bad computation. I don't know of any studies that have looked at this, so I'm not sure we know the answer.