Truncate a custom field value and add it to another

[Janel Bland]

I have three custom fields where the options are components and their weights:

"Motor-450"  "Transmission-750"  etc.

I would like to add the weights for all optional components, and populate a custom field called "Total". 

For my manually triggered automation, I created a variable:

 {{issue.#####.split("-").last.asnumber}}

I don't get any number as a result. Any Ideas how I could complete this task?

[Graham Twine]

Hello @Janel Bland

Do you have Scriptrunner available?

A scripted field may best suite this requirement.

Is the original value stored in a component or a custom field?

The question is a little ambiguous.

[Janel Bland]

I don’t have Scriptrunner. 

The original values are stored in custom fields.