How to round a float in F#?

For reference, there are also built-in F# functions for floor, ceiling, truncate, and round; however, the built-in round function doesn't allow you to specify the precision like System.Math.Round(...) does.

Reference: https://fsharp.github.io/fsharp-core-docs/reference/fsharp-core-operators.html

System.Math.Round (3.21156,3);;
val it : float = 3.212