| Places | Ones | Tenths | Hundredths | Thousandths | |
|---|---|---|---|---|---|
| 1 | |||||
| Number | 3 | . | 8 | 9 | 9 |
| Rounded Number | 3 | . | 9 |
- 8 is in the tenths place and 9 is in the hundredths place
- Since the digit in the hundredths place (9) is greater than or equal to 5, add 1 to the digit in the tenths place (8)
- 1 + 8 = 9, so the digit in the tenths place becomes 9
- The digits to the right of the tenths place are dropped
- 3.899 rounded to the nearest tenth (one decimal place) = 3.9
