930,000
Step-by-step explanation:
To round a digit, in this case a digit in the 10 thousands place, you have to look at the digit next to it. If the digit next to it is 5 or up, round to the nearest larger ten thousand. If the digit is less than 5, round to the nearest lesser ten thousand.
In 940,000, 4 is in the 10 thousands place. The digit next to it is 0, so round down. The nearest lesser ten thousand is 3, so the number becomes 930,000.