So Ten and I work on math every morning for a few minutes.
She will often hum, or tap her feet, or try to carry on a conversation with me while doing a few math problems.
And sometimes Big will come downstairs and try to get my attention, or demand breakfast or something.
I will regularly correct Ten and try to get her to focus on one thing at a time.
That is sort of my thing right now, trying to maintain presence and focus on whatever is at hand (even as I write this, however, I've got about six windows open on my computer, and my cell phone is playing music to my left. At least I've given up IMing.).
Already though, Ten has tried to make the argument to me that she does math better if she's humming, or doing other things.
Of course, her time and her scores don't show this, but kids aren't convinced by evidence, anecdotal or otherwise.
Check out this video on multitasking the next time you try doing ten things at once, or watch your pre-teen in action.