Round 763,400 to nearest ten thousand explain

Okay, so we first need to locate which number is in the ten thousand place.
Ten thousand, is this 10, 000, right? Well that number has 5 digits.
Now go back to 763,400 and starting from the right, count the first 5 digits.
You should stop at the 6.
the rest is easy! Look to the right of 6, there's a 3. Since 3 is less than 5,  you will not round the 6 up to 7. 
SO, you keep the 7 and the 6, but turn the rest of the numbers after 6 into 0s.
Your answer should be 760,000!

I hope I made sense, if not, I will clarify anything you did not understand!