Rounding up to 2 decimal places C#

Question

I'm interested how to round up double variable to 2 decimal places in some a little bit specific way. What exactly do I mean? Math.Round ( number, 2) works fine but... I have for example number like 17.0449999...

Math.Round(17.044999, 2) // 17.04

But in that case i'd like to get 17.05. I found a way how to do this, for example:

Math.Round(17.044999, 3) // returns 17.045
Math.Round(17.045, 2) // returns 17.05

What I would like to ask is there some other/better/more simple way to do that?

[EDIT]:

I think i found that's kinda strange problem. From the beginning:

We talk about specific number. I have to count 5% from a prize and in that case prize is 340,9. When i do calculations in windows calculator 340,9 * 0.05 the result is 17,045. Same result i get when i do calculations in Excel. But when i do same calculations in C# i get something like 17,04499999998. Which is obviously so close to 17.045 that we could easily round it up. But the point is that i can't round up to 3 decimal places every result, because that might change other results.

Seems that is special case or C# calculations are "too accurate".

Answer 1

You can use:

System.Math.Ceiling (n * 100) / 100;

As explained here:

Difference between Math.Floor() and Math.Truncate()

Example:

System.Math.Ceiling (17.044999 * 100) / 100; // Returns 17.05

Answer 2

public decimal RoundDown(decimal i, double decimalPlaces)
{
   var power = Math.Pow(10, decimalPlaces);
   return Math.Floor(i * power) / power;
}

public decimal RoundUp(decimal i, double decimalPlaces)
{
   var power = Math.Pow(10, decimalPlaces);
   return Math.Ceiling(i * power) / power;
}

RoundDown(17.045, 2);  // 17.04
RoundUp(17.045, 2);    // 17.05