-`expression` — A number to be rounded. Can be any [式](../syntax.md#syntax-expressions) 数値を返す [データ型](../../sql-reference/data-types/index.md#data_types).
SELECT number / 2 AS x, round(x) FROM system.numbers LIMIT 3
```
``` text
┌───x─┬─round(divide(number, 2))─┐
│ 0 │ 0 │
│ 0.5 │ 0 │
│ 1 │ 1 │
└─────┴──────────────────────────┘
```
**丸めの例**
最も近い数値に丸めます。
``` text
round(3.2, 0) = 3
round(4.1267, 2) = 4.13
round(22,-1) = 20
round(467,-2) = 500
round(-467,-2) = -500
```
銀行の丸め。
``` text
round(3.5) = 4
round(4.5) = 4
round(3.55, 1) = 3.6
round(3.65, 1) = 3.6
```
**また見なさい**
- [ラウンドバンカー](#roundbankers)
## ラウンドバンカー {#roundbankers}
数値を指定した小数点以下の桁数に丸めます。
- 丸め番号が二つの数字の中間にある場合、関数はバンカーの丸めを使用します。
Banker's rounding is a method of rounding fractional numbers. When the rounding number is halfway between two numbers, it's rounded to the nearest even digit at the specified decimal position. For example: 3.5 rounds up to 4, 2.5 rounds down to 2.
It's the default rounding method for floating point numbers defined in [IEEE 754](https://en.wikipedia.org/wiki/IEEE_754#Roundings_to_nearest). The [round](#rounding_functions-round) function performs the same rounding for floating point numbers. The `roundBankers` function also rounds integers the same way, for example, `roundBankers(45, -1) = 40`.
-`expression` — A number to be rounded. Can be any [式](../syntax.md#syntax-expressions) 数値を返す [データ型](../../sql-reference/data-types/index.md#data_types).