Rounding to the nearest 100 means finding which hundred (100, 200, 300, 400...) a number is closest to. The key is simple: look at the tens digit!
If the tens digit is 5 or more (5, 6, 7, 8, 9):
Round UP to the next hundred ⬆️
If the tens digit is less than 5 (0, 1, 2, 3, 4):
Round DOWN to the previous hundred ⬇️
Find the second-to-last digit (the tens place).
In 567, the tens digit is 6
Since 6 ≥ 5, round UP to the next hundred.
567 is between 500 and 600, closer to 600
567 → 600
| Number | Tens Digit | Direction | Rounded to Nearest 100 |
|---|---|---|---|
| 234 | 3 (< 5) | Down ⬇️ | 200 |
| 567 | 6 (≥ 5) | Up ⬆️ | 600 |
| 850 | 5 (= 5) | Up ⬆️ | 900 |
| 142 | 4 (< 5) | Down ⬇️ | 100 |
| 999 | 9 (≥ 5) | Up ⬆️ | 1000 |
| 1234 | 3 (< 5) | Down ⬇️ | 1200 |
| 3789 | 8 (≥ 5) | Up ⬆️ | 3800 |
500
Previous hundred
567
Tens digit is 6 (≥ 5)
600 ✓
Rounds to this!
Since 6 ≥ 5, we round UP to 600
Round prices for quick estimates
$567 → About $600
Estimate crowd sizes or population
1,234 people → About 1,200
Round sales figures for presentations
$3,789 → About $3,800
Round distances or quantities
567 miles → About 600 miles
=ROUND(567, -2) → 600
The -2 means "round to hundreds place"
round(567, -2) → 600
Math.round(567 / 100) * 100 → 600
The TENS digit
(Second from the right)
5, 6, 7, 8, 9
0, 1, 2, 3, 4
567 → Tens is 6
6 ≥ 5, so round to 600