630
6 630 000 rounded to nearest million is 7 000 000
630
620
630
1000
630 rounded the the nearest hundred is 600. The 6 is the hundred digit and 30 is less than 50, so rounded to nearest hundred is 600.
It is 630, as appears in the question.
630
640
630
23628.64 rounds to:0 to the nearest hundred thousand20 000 to the nearest ten thousand24 000 to the nearest thousand23 600 to the nearest hundred23 630 to the nearest ten23 629 to the nearest whole number/unit23 628.6 to the nearest tenth