C# Check if a decimal has more than 3 decimal places?

Question

I have a situation that I cannot change: one database table (table A) accepts 6 decimal places, while a related column in a different table (table B) only has 3 decimal plac

Answer 1

One more option based on @RodH257's solution, but reworked as an extension method:

public static bool HasThisManyDecimalPlacesOrLess(this decimal value, int noDecimalPlaces)
{
    return (Decimal.Round(value, noDecimalPlaces) == value);
}

You can then call that as:

If !(tableA.Qty * tableA.Unit).HasThisManyDecimalPlacesOrLess(3)) return;