How to calculate cost of good sale

Hello,
in a case, assemble 100 glasses, bread 5 lens, raw material of lens consumed 105, in ERPNext, how to calculate the more cost 5 lens into cost of good sale?

here is what i do:
i use stock entry(issue Type) to issue 5 lens to mark the cost into project. so the cost was calculated, but not in the cost of good sales.