Nearest 10, 100, 1000, 10000, …, million and so on

3671 = 3670, to the nearest 10
3671 = 3700, to the nearest 100
3671 = 4000, to the nearest 1000

15699 = 15700, to the nearest 10 and also the nearest 100
15699 = 15700, to the nearest 100 and also the nearest 10
15699 = 16000, to the nearest 1000
15699 = 20000, to the nearest 10,000

The population of India is 1,437,638,023.
To the nearest 10, this is 1,437,638,020
To the nearest 100, this is 1,437,638,000
To the nearest 1000, this is 1,437,638,000
To the nearest 10000, this is 1,437,640,000
To the nearest million, this is 1,438,000,000
To the nearest billion, this is 1,000,000,000