Rounding larger numbers can be tricky to understand as you get different results depending on what you round to.
For example 12 345 rounded to the nearest 10 is 12 350, to the nearest 100 is 12 300, to the nearest 1 000 is 12 000 and to the nearest 10 000 is 10 000. What you round to will depend on the circumstances and how accurate your rounding needs to be.
These pages look at how to round to the nearest 10 000. In this case the two crucial digits to look at are the ten thousand and the thousands digits.