how to get numbers to a specific decimal place c#

Question

im a newbie doing windows forms c# so i recently wanted to create something like a cashier payment calculation button, but then i got stucked at the rounding part. For example, if the total amount is $40.23, how can i make it round up to #40.25 instead of going down to $40.20? Or maybe $40.26 to $40.25?

the total amount values are get from textboxes and the final after-rounded value will be display in textbox as well. hope i was not being too unclear about my question. thanks guys

problem is you want to round to same numbers of digits. one better solution is get the last digit of number and identify if its lesser or greater . according to that you replace that last digit. - you will get what you want. — Ajay Kumar, Jan 10 '18 at 13:18

score 6 · Accepted Answer · answered Jan 10 '18 at 13:17

6

Try this:

decimal value = 40.23m;
decimal rounded = Math.Round(value * 20.0m, 0) / 20.0m;

Then rounded is 40.25m.

answered Jan 10 '18 at 13:17

Enigmativity

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I fiddled the output for 40.20 to 40.29 : https://dotnetfiddle.net/O5zPB5 seems what OP requires. – Fildor Jan 10 '18 at 13:24
Is there a benefit for using `Math.Round(value * 20.0m, 0)` instead of `Math.Round(value * 2m, 1)`? – Martin Backasch Jan 10 '18 at 14:50
is it possible to use double instead of decimal? sorry for not clearly stating my question before. – Feii Momo Jan 10 '18 at 14:51
@FeiiMomo: [`Math.Round`](https://docs.microsoft.com/en-us/dotnet/api/system.math.round?view=netframework-4.7.1#System_Math_Round_System_Double_System_Int32_) has also an overload for double. – Martin Backasch Jan 10 '18 at 14:58
@FeiiMomo - You're talking about cashier payments so `decimal` should be preferred over `double`. – Enigmativity Jan 10 '18 at 21:45
@MartinBackasch - It's easier in my mind to round to a whole amount and then convert back down. – Enigmativity Jan 10 '18 at 21:45

how to get numbers to a specific decimal place c#

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