/// <summary> /// n! means n × (n − 1) × ... × 3 × 2 × 1 /// For example, 10! = 10 × 9 × ... × 3 × 2 × 1 = 3628800, /// and the sum of the digits in the number 10! is 3 + 6 + 2 + 8 + 8 + 0 + 0 = 27. /// Find the sum of the digits in the number 100! /// </summary> /// <returns></returns> public string Compute() { return(MathLibrary.SumDigits(MathLibrary.BigFactorial(100)).ToString()); }