The Decimal Number custom field extends Atlassian's numbered field, allowing you to display numbers with one, two, or three decimal places.
Create and configure the custom field
To create and configure the Decimal Number custom field, you must be logged in as a user with Jira administrator permissions.
Navigate to Apps → Manage your apps → Fields
Click the Create custom field button on the right side of the screen.
Select Decimal Number and click Next.
Name the field and add a description, then click Next.
Choose the number of decimal places.
Associate the field with the appropriate screens and click Create. You must associate a field with a screen before it will be displayed.