In Google Sheets, the TRUNC function is used to truncate a number to a specified number of decimal places or integer digits. The function syntax is as follows:

TRUNC(value, [places])

"value" is the number that you want to truncate. [Optional] "places" specifies the number of decimal places (positive) or integer digits (negative) to which you want to truncate the number. If omitted, the function will truncate the number to 0 decimal places. Here's an example to illustrate how to use the TRUNC function:

Suppose you have a value of 3.14159 in cell A1, and you want to truncate it to 2 decimal places. In cell B1, you can use the formula:

=TRUNC(A1, 2)

The TRUNC function will truncate the number in cell A1 to 2 decimal places and return the result in cell B1. In this case, the result would be 3.14.