Interface and implementations to map temperature scales to Kelvin scale

KelvinMappers.cs

private interface IKelvinMapper
{
    decimal ToKelvins(decimal value);
}

private class CentigradeToKelvinMapper : IKelvinMapper
{
    public decimal ToKelvins(decimal value) => value + 273.15M;
}

private class FahrenheitToKelvinMapper : IKelvinMapper
{
    public decimal ToKelvins(decimal value) => (value + 459.67M) * 5 / 9;
}

private class RankineToKelvinMapper : IKelvinMapper
{
    public decimal ToKelvins(decimal value) => value * 5 / 9;
}

private class KelvinToKelvinMapper : IKelvinMapper
{
    public decimal ToKelvins(decimal value) => value;
}