Sure, that's low, depending on context. At 6 significant digits, a million-dollar bank account would have a margin of error of up to +/- 5 dollars. And if you

Sure, that's low, depending on context. At 6 significant digits, a million-dollar bank account would have a margin of error of up to +/- 5 dollars. And if you add up a million of any item with 6 significant digits, that's enough for inaccuracy to propagate all the way into your first significant digit. (It would require systematic inaccuracy in one direction, but there are certainly data sets and contexts where that would happen.)