You can round to a specific number of decimal places in Excel using the ROUND function. Here's how:

Syntax:

```excel
=ROUND(number, num_digits)
```

Arguments:

* `number`: The number you want to round. This can be a cell reference (e.g., A1) or the actual number itself (e.g., 3.14159).
* `num_digits`: The number of decimal places to round to.
* Positive values round to the specified number of decimal places (e.g., 2 rounds to two decimal places).
* Zero rounds to the nearest whole number (integer).
* Negative values round to the left of the decimal point (e.g., -2 rounds to the hundredths place).

Example:

* To round the value in cell A1 to two decimal places:

```excel
=ROUND(A1, 2)
```

* To round the number 3.14159 to three decimal places:

```excel
=ROUND(3.14159, 3)
```

* To round the value in cell B2 to the nearest whole number:

```excel
=ROUND(B2, 0)
```

Tips:

* You can use the ROUND function within other formulas for more complex calculations.
* Excel also offers other rounding functions like ROUNDUP (always rounds up) and ROUNDDOWN (always rounds down) for specific rounding needs.