| Places | Ones | Tenths | Hundredths | Thousandths | Ten Thousandths | Hundred Thousandths | Millionths | |
|---|---|---|---|---|---|---|---|---|
| 1 | ||||||||
| Number | 0 | . | 2 | 1 | 6 | 5 | 8 | 4 |
| Rounded Number | 0 | . | 2 | 1 | 7 |
- 6 is in the thousandths place and 5 is in the ten thousandths place
- Since the digit in the ten thousandths place (5) is greater than or equal to 5, add 1 to the digit in the thousandths place (6)
- 1 + 6 = 7, so the digit in the thousandths place becomes 7
- The digits to the right of the thousandths place are dropped
- 0.216584 rounded to the nearest thousandth (three decimal places) = 0.217
