using NCalc;

using System;

​

public class Program

{

    public static void Main(string[] args)

    {

        var expressions = new[]

        {

            "Truncate(512312/Pow(10,Floor(Log10(512312))))"

        };

        foreach (string expression in expressions)

        {

            Expression myExpr = new Expression(expression);

            System.Console.WriteLine(expression + " => " + myExpr.Evaluate());

            if (myExpr.Parameters.Count > 0)

            {

                foreach (var myExprParameter in myExpr.Parameters)

                {

                    Console.WriteLine("Parameter " + myExprParameter.Key +" => " + myExprParameter.Value.ToString());

                }

            }

        }

    }

}