Amp Script to convert decimal value

Question

In date extension there is a text field with name CRT and it contains a decimal value 53.8888889998899988

I want to get an output up to two decimal places that is 53.88.

I am trying to use FormatNumber but when I preview it, I am getting the following error

*The specified attribute or custom object field name was not found for this client.
 Function Call: FormatNumber(@CTR1,D2,en-US)
 Attribute or Field Name: D2*

Please see below code:

%%[
    var @lookupValue
    var @countrow
    var @i
    var @rowCount

    set @lookupValue = "1"
    set @countrow = lookupRows("Total Sent Last 7 days Extract","booleanvalue", @lookupValue)
    SET @i = 1
      set @rowCount = row(@countrow,@i)
      set @CTR1 = field(@rowCount,"CRT")
      set @CTR1 = FormatNumber(@CTR1,D2,en-US)   
      ]%%
      <table width="650" border="0" cellspacing="0" cellpadding="0" style="width:100%; max-width:650px; padding:10px; display:block; border:1px dashed red;">
        <tr>
          <td>
            <strong>No of Emails Opened: </strong> %%=field(@rowCount,"TotalEmailOpens")=%%<br>
            <strong>CTR: </strong> %%=v(@CTR1)=%%%<br>


          </td>
        </tr>
      </table>

Answer 1

You need double quotes around the D2 and en-US inside of your call otherwise it assumes they are calls for variables/fields.

Also, I would recommend using Format(@CTR1, "N2", "en-US") instead - this will allow it to format numbers stored as strings as well as any that are stored as numbers/decimals.

Answer 2

I'd try using FixePoint (F2) as the format type within the FormatNumber AMPscript function.

Example:

%%=FormatNumber(53.8888889998899988, "F2", "en-US")=%%

Result: 53.89