FLOOR.PRECISE is a function in Google Sheets that rounds a given number down to the nearest specified multiple, without adjusting the fractional part of the number.

The function takes one or two arguments. The first argument, number, is the number that you want to round down. The second argument, significance, is optional and specifies the multiple to which you want to round down. If the significance is not specified, it defaults to 1.

Here's an example:

Let's say you have a number of 12.7 that you want to round down to the nearest multiple of 0.5. To use the FLOOR.PRECISE function in Google Sheets, you would write:

=FLOOR.PRECISE(12.7, 0.5)

This function will return the value 12.5, which is the nearest multiple of 0.5 that is less than or equal to 12.7, without adjusting the fractional part of the number.

Similarly, if you have a number of 8.2 that you want to round down to the nearest multiple of 2, you would write:

=FLOOR.PRECISE(8.2, 2)

This function will return the value 8, which is the nearest multiple of 2 that is less than or equal to 8.2, without adjusting the fractional part of the number.