Как округлить все float до тысячных?

Vector3 p = pos;
float x = (float)Math.Round((decimal)p.x, 3);
float y = (float)Math.Round((decimal)p.y, 3);
float z = (float)Math.Round((decimal)p.z, 3);
pos = new Vector3(x, y, z);

float x = 1.99999999f;
string s=x.ToString("F3"); // "2.000"

public static class Extension { public static string Round(this float number) => number.ToString("0.000"); }

float x = 1.9999999999F, y = 2.567777777777F, z = 0.599999999999F;
Console.WriteLine(x.Round());
Console.WriteLine(y.Round());
Console.WriteLine(z.Round());

            float x = 1.56000001F, y = 1.56000004F, z = 1.56100001F;
            string xs = x.Round(), ys = y.Round(), zs = z.Round();
            if(xs == ys && zs != ys)
            {
                {отправялем xs ys zs }
            }

            if (Math.Round(x, 3) == Math.Round(y, 3) && Math.Round(z, 3) != Math.Round(y, 3))
            {
                string xs = x.Round(), ys = y.Round(), zs = z.Round();
            }