The `Math.Round(...)`

function has an Enum to tell it what rounding strategy to use. Unfortunately the two defined won't exactly fit your situation.

The two Midpoint Rounding modes are:

**AwayFromZero** - When a number is halfway between two others, it is rounded toward the nearest number that is away from zero. (Aka, round up)
**ToEven** - When a number is halfway between two others, it is rounded toward the nearest even number. (Will Favor .16 over .17, and .18 over .17)

What you want to use is `Floor`

with some multiplication.

```
var output = Math.Floor((41.75 * 0.1) * 100) / 100;
```

The `output`

variable should have 4.17 in it now.

In fact you can also write a function to take a variable length as well:

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

`Math.Round`

?