DD6 is prone to throwing drama fits in which she pretends to not understand something very basic. My tactic is to take her at her word and walk her through it until she grabs the pencil out of my hand and starts doing the problem for real.

But today, after she got over the drama and buckled down to actually trying, it became apparent that she really couldn't reliably name 407 vs. 470, for example. (Even though, one at a time, she can identify the hundreds, tens, and ones places.) I've always known she had a weird area of weakness in small-scale spatial relations, compared to the rest of her cognitive profile, so this makes perfect sense.

I don't think it's a huge roadblock, we worked on it for several minutes and she started getting the hang of it. But I have to wonder how long this would have gone uncorrected? And how much math frustration it would have given her?

I don't blame Tiny Private School, the teacher does an awesome job of tracking twelve moving targets. (Meaning twelve kids, each on their own trajectory.) But it seems like there's no substitute for one-on-one. Here's to being an "over-involved" parent!

I have high hopes that a bunch of math stuff is going to suddenly become much easier for her, just by clearing up this one weak spot.

well spotted mom!

I've worked with a lot of K-2 kids and it's pretty common to see kids who understand the base ten system, but have trouble comparing numbers with scrambled digits. The more numbers you add, the more complicated it gets. (E.g. Order 5,123; 5,321; 2,315; 5,213) I expect my NT 2nd graders to be able to do problems like this example, but it can be hard for the eye to move back and forth. We often use the strategy of "stacking" (placing the numbers on top of each other so that the place values are lined up), which makes it easier to see the differences. Most of my kids compare this to alphabetical order - you start on the left and work toward the right.

Maybe stacking would help her see this difference?

Good info to know, KathrynH! DD's problem was more basic -- when confronted by just a single 3-digit number, she had trouble naming it correctly if there was a zero anywhere in it.

It seems likely she will also confront the problem you're describing, so I'll keep it in mind.

I see the issue now. I must have read over your post a little too hastily. Actually having trouble naming numbers with zeros can be tricky for a lot of kids too.

I also see a lot of blank stars when giving kids numbers in the hundreds or thousands that fall in the teens (e.g., 514, 711, 612). 12 is particularly difficult for most kids. But a little practice generally remedies this.

DD6 also had that problem a few months ago. Her teacher said it was very common and just needed some practice. We did some random writing and saying practice at home for about a week or two and she was fine with it.
So, I would agree with KathrynH is is not actually a big deal, but is something that is good to catch.