Round to the nearest ten thousand 276,431

Ten thousand is 10 000, which means that our number will have 4 zeros at the end.

so is i

270 000

?

well, the question is: is the number that the first 0 replaced 5 or higher? yes, yes it is, it is "6"

so we have to make the first not-replaced number bigger by 1:

the correct answer is 280 000