Round to 25, 50, 75, 100

Question

I\'m not a Math person so I\'m having a hard time to come up with a calculation to round the decimals to 25, 50, 75 and 100. And this will not be the typical round off because t

Answer 1

I suggest using types without floating point.

decimal RoundNearestCents(decimal price) {
    // no problems with floating point as all calculations are exact
    return Math.Floor((price * 100 + 24) / 25) * 25 / 100;
}

-- Why is your price string?

-- Because it's coming from a textbox.

I assume your textbox should support limiting your input to decimal numbers with at most 2 decimal places. So its value will be decimal already. However I don't know what is your application type. If you still want to accept string then consider using decimal.TryParse method to convert it to decimal.