It is 6000000.
Round to the nearest million and get 6 000 000
To round off 128,674 to leave one nonzero digit, you would round it to 100,000.
It is 3000000000.
It is 300000.
It is 300.
It is 500.
500
It is 3000000000.
It is 5000000.
500500
It is 90000.
485 6 592 128 674