| Places | Ones | Tenths | Hundredths | Thousandths | Ten Thousandths | |
|---|---|---|---|---|---|---|
| 1 | 1 | |||||
| Number | 0 | . | 2 | 0 | 9 | 9 |
| Rounded Number | 0 | . | 2 | 1 | 0 |
- 9 is in the thousandths place and 9 is in the ten thousandths place
- Since the digit in the ten thousandths place (9) is greater than or equal to 5, add 1 to the digit in the thousandths place (9)
- 1 + 9 = 10, so the digit in the thousandths place becomes 0, and 1 is added to the digit in the hundredths place (0)
- 1 + 0 = 1, so the digit in the hundredths place becomes 1
- The digit in the ten thousandths place is dropped
- 0.2099 rounded to the nearest thousandth (three decimal places) = 0.210
