How keep number field in a combobox from displaying decimals

I have a combobox that is displaying decimals in a field named 3DigitCode and I cannot figure out why.

Here is the SQL of the code behind the combobox:

SELECT tblPartNumberItemMasterTable.ItemMasterID, tblPartNumberItemMasterTable.[3DigitCode] AS Code, tblPartNumberItemMasterTable.DataMasterDescription1 AS [Description 1], tblPartNumberItemMasterTable.DataMasterDescription2 AS [Description 2]
FROM tblPartNumberItemMasterTable
ORDER BY tblPartNumberItemMasterTable.[3DigitCode];